Othello Reversi Glossary


Othello Reversi Glossary


Othello is a classic game that is popular as an educational game for children.

The rules are simple and clear, but if you want to beat an advanced player, you’ll have to use your brain to win.

Like shogi and chess, there is a fixed set of rules.

Your winning rate will vary greatly depending on whether you know these rules or not.


There is also a game called “Reversi” that has the same rules as Othello.

Reversi and Othello have the same rules, but the difference between the two is the number of squares on the board.

Reversals are performed on a board larger than Othello.

(Because of that, I often think about winning)


This time, I have put together a glossary of simple terms for Othello and Reversi that anyone can play.

If you want to be able to win at Othello or Reversi, please take a look.


bad form

The unique arrangement of stones that indicates an unfavorable shape is collectively called “bad shape.”

Physically, it refers to a situation where the opponent’s stone is placed on the edge or corner, making it easier for the surrounding stones to be overturned.

Bad shapes originate from the placement of specific stones on the board, such as blocks (pure blocks, semi-blocks), wings (pure wings, semi-wings), and walls.

If you create these shapes, you are likely to be at a disadvantage.

Each move is an important element that determines the fate of the board, and it’s fun to devise strategies to avoid falling into a bad shape.


Bad move

To be exact, it is pronounced “akshu”. This refers to bad moves that easily give your opponent a good move.

A move that is not the best or is chosen even though there are better moves in the situation, and is generally considered a bad move by beginners who make it without thinking at the beginning.

Othello’s bad move is a moment when a momentary judgment or misreading occurs, and it is also an opportunity to experience the tension of making the next move.



This refers to a method of securing the edge by throwing stones at the opponent’s edge.

If the opponent does not secure an edge, it is easier for you to obtain it instead of taking the edge, so it is somewhat forced.

However, guessing without meaning is a lax move, and a strategy is required to gain profit with each guess.

Guessing is one of the basic skills of Othello and requires tactical positioning and reading.

It’s a simple yet very effective method, and it’s one that brings out the real thrill of the game.

Sometimes the situation changes in unexpected ways, and the surprise and joy of that moment is fun.


ultimate end

This refers to the ultimate strategy of securing a large amount of stones at the end of the game and winning by leaving a lot of your own stones even if your opponent hits you repeatedly.

This situation is important to ensure victory in the final stages of the game.

The ultimate ending is a moment where you can feel the real thrill of Othello’s strategy and mutual reading, and it is a fun element that heightens the tension and excitement of the game.

The winner is happy and says, “…it was dangerous,” and the loser is, “Huh? Why isn’t it enough?” (angry).

Please note that this has nothing to do with certain summoning magic.


memorize othello

This refers to the strategy of memorizing the basics of the early stages. You can make very quick moves in the early stages, but if you forget, it will be difficult to recover later.

Recently, analysis of the early stages using software has progressed, and memorization has become common at Dan level.

By memorizing important phases and steps, such as specific openings, routines, or ultimate endings, you can use them in your gameplay!

Memorizing Othello is a way to enjoy the depth of strategy and mutual reading, and it is a tool for making appropriate moves depending on the situation.


Kenichi Ishii

He is currently an 8th dan, and is a talented athlete who won the 7th and 11th world championships.


Ishibashi style

A strategy that is characterized by a progression that involves repeating one move from the beginning.

This play style originates from Japanese player Nobuhiro Ishibashi and is characterized by aggressive attacks and strategy.

In the Ishibashi style, you may take risks depending on the situation, but you aim to steadily build an advantage while controlling the opponent’s reaction.

It is a play style that requires courage and strategy, and the ability to respond flexibly is important.


One stone return

One stone return refers to the strategy of reversing only one stone of the opponent in the Othello situation.

This technique is considered to be an effective approach, especially for beginners, as it has the effect of stabilizing the situation compared to strategically aggressive large-volume taking.

It’s a simple yet profound technique that serves as the gateway to strategy.


Hiroshi Inoue

Hiroshi Inoue is a legend in the Othello world, having won the first and third World Othello Championships.

His accomplishments have left a notable mark in Othello’s history.

He is one of the true champions of the Othello world and is a dream come true for many players.


one road

Ippondo refers to a specific situation encountered in the final stages of Othello, where the winner or loser is almost decided, and the number of correct answers is limited.

In this phase, subtle strategies determine the difference between victory and defeat.

The tension you feel when you reach this point at the end of the game is one of the best parts of Othello.



Wings are rows of stones of the same color that form along the sides of Othello’s board.

This shape has a huge impact on the flow of the game, from offensive to defensive positioning.

Winging is an advanced tactic that can be used flexibly depending on the situation.



Usagijoseki is one of the four major joseki in Othello, and refers to a strategy that follows a specific procedure.

This classic is easy to understand the basic strategy, making it an accessible choice for beginners.

Usagijoseki is a very useful joseki for learning the basics of Othello.



Ushijoseki is one of the four major Othello joseki, and it is a joseki that has many variations, especially in the initial steps.

Progressing according to this standard has a wide range of possibilities in the development of the game.

Gyujoseki is a joseki that holds the key to a deep strategic understanding of Othello.




It is a strategy developed based on the rabbit rule, in which the game progresses from f5, d6, c5, f4 in the early stages, and then black moves to d3.

If White chooses anything other than f4, it will be a big mistake and Black will have a powerful trick.

If handled properly, it puts Black at a slight disadvantage, but it’s a tactic that can be countered by deep research.

It’s a classic game where you can enjoy a perfectly balanced attack and defense, and the strategic maneuvering is fascinating.


Back bat joseki

It is a method that shows a development similar to bat joseki based on the jump progression.

The uniqueness of the name symbolizes the diversity of Othello.


A (A hit)

The strategy is to hit squares near the center near the sides of the board, and refers to eight specific squares.

Generally speaking, it is said that when in doubt, hit A, but you need to be careful as this may be inappropriate depending on the situation.

It has a simple yet profound tactical meaning.


X (X hit)

It refers to how to play in the four squares diagonally inside one of the corners, and although it is often disadvantageous if you play recklessly in the early stages, depending on the situation, it can be an important move to advance the game to your advantage.

This is a strategically deep move where timing is important.



Refers to a specific method that develops from Torajoseki.

Othello’s tactics have many established names named after animals, and it’s interesting that each one has a deep strategic value.


Othello Japan

This site provides all kinds of information about Othello, and is packed with tournament information, Othello courses, blogs, and useful software.

There is a wealth of content that helps players improve their skills, such as daily end-game questions and online Othello classes.

It is managed by Tetsuya Nakajima, 8th Dan.

This site is like a treasure chest for Othello lovers.


Osaka branch regular meeting

This is an Othello practice event held once a month in Sakai City, Osaka Prefecture.

It is not an official tournament, and is characterized by an open atmosphere where anyone can participate regardless of rank.

It is also attractive that there is a stone handicap to make it easier for beginners to participate.

It provides a great opportunity to improve your playing while having fun.




This refers to a technical method of striking that eliminates the need to turn back the stones on the inner middle side when placing stones on the sides.

This method often leaves adjacent squares for the next move, and is considered one of the most effective edge-taking strategies.

Hitting on the spot is a symbol of strategic forethought and sophisticated play.


Championship match

This is a competition held on a nationwide scale, and is one of the major tournaments along with the National Meijin Tournament and the All Japan Championship.

Eligibility is limited to players who meet certain winning criteria and seeded players, all of whom compete in the same league.

The winner will be awarded the championship title and the right to participate in the world championship.

The battle for the throne is truly a battle of champions, determining the top of Othello.


othello quest

This app allows smartphone users to enjoy playing Othello against each other and is certified by the Japan Othello Federation.

Created by Yasushi Tanase, it features random matching matches, making it easy to match with opponents of the same level.

The system in which you are awarded tiers as you progress through quests is also attractive.

Othello Quest is a great platform where you can enjoy competitive Othello anytime and anywhere.


Othello Elementary School Grand Prix (OSG)

This is a tournament limited to elementary school students, and those who survive the local qualifying rounds will compete in the national tournament.

This tournament is attended by the most talented young people and serves as a platform for promising young people to shine.

OSG provides a great opportunity for young talent to shine, and the future of Othello is bright.



Fast boat joseki

This is a progression derived from Ushimoto Joseki, in which White plays e7 on the 8th move, resulting in a stone arrangement that resembles the shape of a ship.

This variation move is one of the most popular strategies, even though it may deviate from the best move.

The fast boat joseki is a fascinating tactic for creating creative shapes on the Othello board.


openness theory

The theory is to strategize by quantifying the number of empty squares around a stone, and the smaller the openness around the stone, the more advantageous the move is.

This theory provides rough guidance for tactical selection.

Openness theory is a very useful way of thinking when considering Othello’s strategy scientifically.


give too much back

In an actual Othello match, this refers to the violation of returning more stones than the stipulated number.

This can especially be seen when transitioning from online play to real-life competition.

Clear rules against this behavior apply at tournaments.

The overreturning shows the importance of following Othello’s strict rules.


forgot to return it

This refers to the mistake of not returning the stone that should be returned, and this phenomenon is especially likely to occur in the final stages of the game.

This is also a violation of the rules, and will be handled according to the rules at the tournament.

Forgetting to return something is a part of Othello that requires careful attention and concentration.



It refers to a specific arrangement of the sides and middle sides, and although it may seem evil at first glance, it may actually have the effect of preventing the opponent’s counterattack.

This placement can have tactical significance.

The key is one of the elements that deepens the strategic maneuvering in Othello.


confirmed stone

It refers to stones that can never be returned once they are taken, and increasing these stones is the key to victory.

Determined stones are typically corner and side stones, but hidden determined stones also exist.

The concept of definite stones is an element that highlights the strategic depth in Othello.




This is a technique that accurately calculates the number of stones a player can obtain in their next move when the game is nearing the end.

Especially in close games, this tactic can be the key to victory.

Counting is done at various stages depending on the situation on the board and your ability.

In Othello, where small differences can determine victory or defeat, counting skills are an essential element in formulating precise strategies.



Pointing to the four corners of the Othello board, securing these positions is one strategy that increases the number of confirmed stones and directly leads to victory.

It is advantageous to take the initiative and secure it yourself, but it can backfire if your opponent captures it.

Securing the corner is an important strategy for winning in Othello, and has the power to influence the flow of the game.



Refers to an arrangement in which stones of one color line up in a row and surround part of the board.

This state is difficult to be attacked by the opponent, but it also comes with strategic disadvantages because you can’t hit that part either.

Although walls are defensive, they are important placements for both sides in the game.


Kansai Championship

This is a large-scale Othello tournament held every year in the Kinki-Hokuriku region, where players compete in two divisions: those with Dans and those with Kyu.

In particular, the winner of the dan category is awarded the title of 4th dan, making it a very prestigious competition.

The Kansai Championship is a place for Othello enthusiasts to gain honor and improve their skills, and is a major goal for the participants.


loose hand

Refers to a careless or strategically inappropriate move that can give an opponent an opportunity to turn the game on its head.

Sometimes you can complicate situations that could have been easily won by choosing the right move.

Depending on how loose it is, it may actually be considered a bad move.

A slow move is one of Othello’s subtle traps that makes a tense game more difficult.


Complete reading

Mentally simulate all possible steps leading up to the end of the game and arrive at the most advantageous outcome.

With computer software, there are around 30 moves available, but for a human player, the prediction limit is around 10 moves.

Complete reading is a skill that requires ultimate tactical acumen and planning in Othello.


demon god

Eiji Tamenori’s nickname comes from his outstanding technique and overwhelming presence in Othello.

The nickname “Kijin” shows how Tamenori’s play style is a source of fear for his opponents.


Game record

It is a record of the Othello game process, and the specific steps are written using alphabets and numbers.

This record is extremely important for analysis and learning.

Game records are an essential resource for learning Othello strategies and techniques.


questionable hand

An unexpected move that differs from the opponent’s intention is often considered a bad move, but if the move is excellent, it may be evaluated as an “exquisite move.”

The questioner is an interesting element that shows the depth of Othello and the psychological warfare between players.


inverse even number theory

In order for Black to gain an advantage, this strategy leaves an odd number of empty squares that White cannot play towards the end of the game.

This theory forces White to pass in the late stages, allowing Black to make consecutive moves.

The reverse even number theory is one of the key strategies in Othello’s clever plan for victory.


rank (person)

It is part of the ranking system that shows the player’s ability in Othello, and refers to the rank below the dan.

Kyu rank usually indicates the progression of skill improvement from beginner to advanced, and is a step toward promotion to dan rank.

The grade system is a great way to give people new to Othello a goal and a concrete path to progress.


centripetal theorem

A theory that explains the importance of controlling the center of the board in Othello.

By controlling the center, it is said that it is easier to maintain an advantageous position throughout the game.

The centripetal theorem is extremely important as a basis for strategic thinking and teaches us how the power of central control can influence the game.


Kyoto Open

This is one of the Othello tournaments held in Japan, and is an open tournament set in Kyoto.

Many players gather and engage in fierce competition.

The Kyoto Open is held in the historic city of Kyoto, further enhancing the appeal of Othello and providing players with an unforgettable experience.



Refers to the state of the board at a specific point in the Othello game. The position is an important element in reading the flow of the game and is an important indicator when deciding the next move.

The ability to understand and analyze situations is a barometer of Othello’s mastery and is essential to enjoying strategic depth.


cut back

In Othello, a method of cutting off the opponent’s advantageous development and conversely connecting it to one’s own advantageous development.

It can be a turning point in a strategic situation.

Switchbacks are the key to getting the flow of the game in your favor, and a good switchback can often decide the outcome of a match.


Goldfish joseki

One of Othello’s tactics, a standard method used in specific situations. The aim is to create an advantageous situation by pushing the opponent into a corner.

As the name suggests, goldfish joseki is a tactic for cornering your opponent like a goldfish, and it provides an enjoyable side of strategic maneuvering.


even number theory

The even number theory is one of the important strategies in the end game of Othello.

The theory is that by maintaining an even number of empty squares, you will ultimately create an advantageous situation.

Having an even number of empty squares increases the chance that your opponent will be forced to pass, giving you an advantage.

The even number theory is a sophisticated theory that requires calculated strategy and foresight for Othello’s victory.


black number

Black number refers to the player who has a black stone at the beginning of the game of Othello.

In Othello, Black plays first and has the right to start the game.

This right of first move plays an important role in strategic planning, especially in the early stages of the game.

Black’s starting the game as the first player is the starting line of psychological warfare in Othello’s battle.


good shape

Favorable shape refers to the arrangement and shape of stones that are advantageous in Othello.

This shape means taking an aggressive position and arranging the stones so that you can expect advantageous developments in the future.

Being in good shape is a key factor in gaining an advantage during the game.

Good form is the key to victory, combining beauty and strategy on the Othello board.


good move

A favorable move refers to a particularly advantageous move in Othello.

This is a good tactical move that can change the course of the game or solidify your advantage.

A good move has the power to change the face of Othello in an instant, testing the player’s insight and creativity.


Kobe open

The Kobe Open is an Othello tournament held in Kobe City, Hyogo Prefecture.

Many players, both professional and amateur, participate in this tournament and compete in their skills and strategies.

The Kobe Open provides a great opportunity for Othello enthusiasts to come together and share their skills and passion.


high dan

A high-level player refers to a player who has a high level in Othello.

These players have years of experience and research, and have excellent tactical understanding and technique.

High-level players are true masters in the world of Othello, and there is always something new to learn from their play.


bat joseki

The bat joseki is one of the strategic patterns in Othello that develops from a specific initial position.

This joseki got its name because its characteristic shape resembles the wings of a bat.

When used effectively, it can create an overwhelming advantage over your opponent.

As the name suggests, Komori Joseki is a clever tactic that engulfs the opponent in darkness.


best move

The best move is the move that produces the best possible outcome in a given situation.

This move means that the player makes the most effective choice to win.

The best move is a clear light that illuminates Othello’s path to victory.



Reenactment is the re-enactment of past Othello matches or specific aspects.

This allows you to analyze and learn strategies and procedures.

Reenactment is the key to honing your current skills through the great games of the past.



Submarine is a specific tactic in Othello that involves making an unexpected attack from below on your opponent.

This tactic allows you to invade your opponent’s territory from unexpected angles and create an advantageous situation.

Submarines represent unpredictable, game-changing attacks.


C (C hit)

C hitting refers to a method of hitting a specific position on the Othello board, especially the side near the center.

This strategy strengthens control in the center of the board and aims for advantageous developments.

C-hitting opens the way to victory by skillfully manipulating the center of the board.


Second best move

A second-best move is a move that is second to the best move and has a higher probability of producing a better result.

This move may be used when the best move is not found or as a strategic choice.

Second-best offers flexible strategic options while always striving for the best.


Time saving (Othello)

“Time saving” in Othello refers to tactics and methods to efficiently proceed with specific situations and overall gameplay.

This approach aims to quickly find the optimal move within a limited consideration time and advance the game in an advantageous manner.

Time-saving strategies are an important element in Othello’s psychological warfare, which requires quick decision-making and efficient play.


designated stroke

A “designated move” refers to a situation in an Othello game where the move to be made is determined in advance based on a specific method or rule.

This method may be used for training or tactical practice in specific situations.

By using designated strikes, you can deepen your understanding of a player’s response abilities and strategies in specific situations.


Reluctant X-stroke

“Reluctant X-hitting” refers to the reluctant move to the X position (one position away from the corner) in order to avoid a very disadvantageous situation in Othello.

This move is often defensive and is only used when there are no better options.

The “reluctant X-stroke” symbolizes the difficult choices a player must make when faced with a difficult situation.


sharp rose

“Sharp Rose” is one of the specific developments and strategies in Othello, and refers to a progression with sharp aggression and calculated risks.

This term was named because of its beautiful and effective offensive deployment.

The Sharp Rose represents the perfect combination of sophisticated tactical beauty and meticulous planning on the Othello board.


Obstruction stone

“Block stones” refer to stones that are disadvantageous or obstructive to the player’s own strategy and development in Othello.

These can be placed intentionally by the enemy or caused by your own carelessness.

Obstacle stones are an important element of Othello’s strategic maneuvering and brain battles on the board.


final stage

The “late stage” in Othello refers to the final stage of the game, when there are fewer empty spaces and the winner or loser is about to be decided.

This stage requires strategic thinking and precise calculations, and is directly linked to the outcome of the game.

The final stage is the climax of the game, where Othello’s tension and excitement reach a climax.


seed stone

Seed stones are stones scattered in Othello to create an advantageous situation in the future.

These become strategic points during the course of the game and may play a key role in later developments.

Seed stones are like investments in the future in Othello and add strategic depth.



Elimination refers to intentionally removing stones or placements that are advantageous to the opponent in Othello.

This action allows you to disrupt your opponent’s strategy or create an advantageous situation for yourself.

Elimination is the art of drawing the flow of the game towards you by destroying your opponent’s plans.



Joseki refers to the effective initial steps known from Othello.

These are developed through years of experience and analysis, and form your early game strategy.

The joseki form the basis of Othello and provide a solid starting point.


Competitive X hit

The winning X move refers to an important move that has a high possibility of determining the outcome in the game of Othello.

This move, which is usually played next to the corner of the board (point X), is a high risk, but also an opportunity for big rewards.

The winning X-stroke is a bold and strategic move that determines the outcome of Othello.


early stage

The opening phase refers to the initial stage from the beginning of the Othello game, and the moves made during this period are an important foundation that determines the flow of the entire game.

The beginning is a very important phase that shapes the future development of Othello.


White number

The white number refers to the player who controls the white stone in Othello.

Since Black is on the play, White always starts the game on the draw.

White is in a challenging position, forcing him to think of a strategic response to Black’s move.


swiss method

The Swiss format is a tournament format used in many competitions, including Othello, in which participants play an equal number of matches and are ranked by points.

This method ensures that everyone is guaranteed a certain number of games, allowing for a fairer competition.

The Swiss method is a great way to ensure fairness and efficiency in large-scale Othello competitions.


Illustrated quick guide to Othello

Illustrated Quick Guide to Othello is a teaching material or book that easily explains the rules, tactics, and techniques of Othello using diagrams and illustrations.

These are very useful for Othello beginners to learn the basics of the game as well as advanced techniques.

As a visual learning tool, Illustrated Quick Guide to Othello is a great way to introduce the fun and depth of Othello to a wider audience.



A stoner is a tactic used in Othello to trap an opponent in a particular situation.

This tactic involves predicting that your opponent will make a certain move and using that reaction to your advantage.

The stoner is one of Othello’s most ingenious traps.


stoner break

Stoner breaking is a counterattack technique that nullifies the opponent’s stoner tactics in Othello and creates an advantageous situation.

This technique requires a high degree of insight to see through the opponent’s plans and take countermeasures.

The stoner break is a tactic that shows the true value of ingenuity and responsiveness in Othello.


Corner (corner)

Corner (corner) refers to the squares at the four corners of the Othello board. Once the corner stone is overturned, it cannot be taken by the opponent again, so it is considered a very important strategic point.

The cornerstone is a source of enduring superiority in Othello.


stone difference

Stone difference refers to the difference in the number of stones between you and your opponent in Othello.

The one with the most stone difference at the end of the game is the winner. This number is an important indicator for determining strategy during the game.

The stone difference is a simple but important element that determines the outcome of Othello.


Koku count

The number of stones refers to the total number of your stones on the Othello board.

At the end of the game, the player with the most stones is the winner.

The number of stones is a direct guide to Othello’s victory.


stone loss

Stone loss refers to the act of putting your stones at a disadvantage by making a specific move in Othello.

Avoiding stone damage and maintaining advantageous stone placement will lead to victory.

Stone loss is a strategic pitfall that should be carefully avoided in Othello.



Zebra is a piece of Othello situation analysis software, a tool that helps players find the best moves in various situations.

It uses advanced algorithms to suggest the best choice among possible moves.

Zebra is a valuable digital coach for players who want to improve their Othello skills.


First come first served

First-come, first-served is a system in which when registering for an Othello tournament, etc., the first person to apply gets the right to participate.

This will be introduced when there is a limit on the number of people, so it is important to apply early.

First-come, first-served is a fair way to encourage systematic registration for popular tournaments.


All Japan Othello Championship

The All Japan Othello Championship is the most prestigious Othello tournament in Japan, sponsored by the Japan Othello Federation.

Top players from all over the country gather to compete to be the best in Japan.

The All-Japan Othello Championship is a dream stage for Othello players, where the highest level of competition takes place.



In Othello, annihilation refers to removing all of your opponent’s stones from the board without leaving any stones behind.

This is a very rare situation and can occur when there is an overwhelming difference in power.

Annihilation is a rare phenomenon in Othello that symbolizes overwhelming victory.


Both sides are dangerous

A two-way risk rule refers to a rule that creates a high-risk situation for both players in Othello.

In situations like this, each move greatly affects the outcome of the game, so careful play is required.

The two-way danger set is a thrilling development that takes Othello’s tactics to the maximum.


both sides hit

Double c-hitting refers to a strategy in Othello in which both players hit stones on the center line (C line).

This strategy aims to control the board from mid to late game.

Both sides are a tactic that allows players to enjoy intelligent bargaining over control of the center.


Instant hit

Immediate action refers to making a move intuitively without thinking long in Othello.

This tactic is especially used when there is a time limit or when you want to put pressure on your opponent.

Immediate attacks are a dynamic tactic that uses intuition and speed as weapons to overwhelm the opponent.


Soft hitting

Soft hitting refers to the act of finding the optimal move in Othello using computer software.

With software support during games, players can make more strategic and calculated moves.

Soft hitting is a modern approach that takes advantage of advances in technology to deepen Othello tactics.



It is a colloquial name for soft hitting and can be seen on the internet. This name is derived from the pronunciation of “sofu”.



bulk quantity

Mass picking is a tactic in Othello in which you overturn many of your opponent’s stones with one move.

While this technique may seem advantageous in the short term, it may give your opponent a strategic advantage in the long term.

Although it may seem attractive at first glance, it is a technique that requires careful judgment when formulating a strategy.



Vertically taking is a method of flipping your opponent’s stones vertically on the Othello board.

This tactic is used to increase control of the board and secure advantageous positions for later developments.

Vertical play can be said to be the most basic of basics in building an advantage on the board.


vertical killing

Tateri-satsu is a counterattack technique in which you purposely lure your opponent to take advantage of you and use it to your advantage.

This tactic requires a high degree of predictive ability and strategic thinking.

Vertical killing is a sophisticated strategy that takes advantage of your opponent’s plans.


Raccoon dog joseki

The raccoon joseki is one of the tactical patterns adopted in certain situations in Othello, and is characterized by flexible responses and unexpected moves.

This joseki aims to create an advantageous situation by confusing the opponent.

Tanuki joseki is a fascinating tactic that creates unpredictable developments.


seed stone

Seed stones are stones placed on the board to create strategic advantages in the future.

These are expected to play an important role in later phases.

Seed stones add strategic depth to Othello as an investment in the future.



Rules refer to the knowledge and principles related to Othello’s tactics and theories.

It can also refer to a specific strategy or method.

Tamenori lays the foundation for a deep understanding and improvement of Othello.



The middle stage refers to the stage between the beginning and the end of Othello’s game progression.

In this phase, the battle for strategic positioning and advantageous positioning takes place.

The middle stage is an important phase that determines victory or defeat, and it is a phase that tests your strategic thinking.



The middle side refers to the side closest to the center on the Othello board.

Controlling this area is important as it influences the strategic flow of the entire board.

Securing a favorable position in the middle is often the key to gaining an advantage throughout the game.

Dominance in the middle is a symbol of quiet power.


Tsubame joseki

Tsubame joseki is one of the specific steps adopted in the opening phase of Othello, aiming to create a specific shape.

This joseki is especially flexible and aggressive, and can force the opponent into unpredictable situations.

Tsubame joseki is a tactic that hides cunning within its elegance.


Tezuka System II

Tezuka System II is one of the algorithms and systems used for Othello situation analysis and strategy planning.

This system enables deeper position analysis and highly accurate move recommendations.

Tezuka System II is the embodiment of advanced technology that will shape the future of Othello.


a dead stop

A stall is a situation in Othello in which a player is unable to make an effective move and is forced to transfer the next move to his opponent.

This condition often results in a strategic disadvantage.

A stalemate is a moment that reminds us of the importance of strategic planning.


bullfighting joseki

Bullfighting joseki refers to a series of steps aimed at building an offensive phase in Othello.

This standard involves actively challenging the opponent’s position and applying pressure to gain an advantage.

Bullfighting joseki is a tactic that brings tension and dynamism to the game.


Bullfighting A (snake) joseki

Bullfighting A (hebi) joseki is a variation of bullfighting joseki, characterized by a more cunning and calculated procedure.

This joseki creates an advantageous situation by confusing the opponent and catching them off guard.

Smooth and unpredictable as a snake, the bullfight A joseki is a tactical work of art.


Bullfighting B (raccoon dog) joseki

Bullfighting B (raccoon dog) joseki is also a form of bullfighting joseki, which pursues maneuverability and varied procedures.

This standard technique uses flexibility and surprise to overwhelm the opponent.

Bullfighting B joseki is a strategy to be as smart as a raccoon dog and outwit your opponent.


Bullfighting C joseki

Bullfighting C joseki is one of the joseki that aims for an aggressive development in the Othello situation.

This joseki is characterized by tactics that actively control the midfield and keep pressure on the opponent.

Bullfighting C Joseki is an attractive choice for players looking for game-leading momentum and strategic acumen.


Tiger A (cat) joseki

Tora A (cat) joseki is a variation of tora joseki, and is characterized by delicate and agile play.

This routine involves not overlooking your opponent’s small mistakes and using them to gain an advantage.

Agile and cunning like a cat, Tiger A Joseki is attractive for its strategic depth.


Tiger B (sheep) joseki

Tora B (sheep) joseki is another variation of tora joseki in Othello, which pursues calm and steady tactics.

This standard is to take a long-term perspective and aim to steadily build an advantage.

It is a classic that teaches us the importance of quiet, steady effort like a sheep.


Tiger C (Swallow) Joseki

Tora C (tsubame) joseki is a form of tora joseki that emphasizes speed and mobility.

This standard aims to gain an advantage by quickly deploying and launching unexpected attacks on the opponent.

This is a standard game that requires the ability to be as quick as a swallow and control the flow of the game.


Tora D joseki

Tora D Joseki is a tactic that aims for a particularly aggressive development in the Tora Joseki series.

The goal of this standard is to gain an early advantage in the game through aggressive attacks.

Tora D Joseki is a choice that shines with bravery and an aggressive attitude.


Tiger E joseki

Tora E joseki is a joseki that aims for the most balanced strategy among multiple tora joseki.

This standard emphasizes the balance between attack and defense, and challenges opponents with flexible strategies.

Tiger E joseki is a tactic that symbolizes harmony and balance on the Othello board.


tiger joseki

Tiger joseki is one of the basic joseki in Othello, and allows for a variety of developments and strategies.

This set of rules is intended to build a solid foundation for the early to mid-game.

Torajoseki is the basic of basics that teaches you the diversity and depth of strategy in Othello.



The game is based on a vertical strategy, and the situation is even.



Diagonal cut

In Othello, slanting refers to the technique of sandwiching the opponent’s stone on a diagonal line and flipping it over.

This tactic is especially effective in the center of the board and near the corners, and has the potential to greatly change the flow of the game.

The diagonal take is a sharp move that brings unexpected changes to Othello’s board and surprises the opponent.



Sorting is a tactic used in Othello to overturn multiple stones lined up in a straight line at once.

It can be done on either horizontal, vertical, or diagonal lines, and when used effectively it strengthens your control of the board.

Sorting is a basic but powerful way to teach the importance of strategic stone placement and board control.


cat joseki

Nekojoseki is one of Othello’s tactics, which is characterized by the deployment of particularly cunning and unpredictable steps.

This standard aims to create an advantageous situation by confusing the opponent and increasing uncertainty in making plans.

Nekojoseki is a fascinating and original tactic that symbolizes the psychological warfare and maneuvering that takes place on the Othello board.



buffalo joseki

Buffalo joseki is one of Othello’s tactics, and its purpose is to create a particularly strong structure.

This joseki aims to restrict the opponent’s movements and gain advantageous development by firmly controlling a specific part of the board.

Buffalo Joseki is a solid strategy that has a constant force on the Othello board.



Airplane refers to a tactic or situation named after the arrangement of certain stones in Othello that resembles the shape of an airplane.

This placement can be the basis for building advantageous positions in certain situations.

The airplane symbolizes the creativity and strategic beauty of Othello’s strategic placement.


sheep joseki

Hitsujijoseki is one of Othello’s tactics, and refers to a procedure that is gentle yet has strategic depth.

This technique aims to quietly create an advantageous situation by gradually increasing the pressure on the opponent.

Hitsujijoseki has a strategic sharpness hidden within its calm appearance.


flat rose

A flat rose refers to the state in which the stones on the Othello board are flat and do not have a specific direction.

This arrangement allows for flexible strategies in the progression of the game.

The flat rose represents Othello’s pursuit of balance and maneuverability.


snake joseki

Snake joseki is one of the tactics used in Othello, and is characterized by a smooth and cunning development.

This set of rules aims to create an advantageous situation by skillfully guiding the opponent and making them make unintended moves.

The snake joseki embodies the skill of Othello’s cunning and calculated movements on the board.


Side A・A strike

Side A/A hitting refers to the strategy of hitting a stone near the center of the side of the Othello board (A line).

This method is used to strengthen control of the board and give advantage to developments from the center.

Edge A/A is a basic but important tactic in Othello that emphasizes the importance of central control.


Side B/B striking

Side B/B hitting refers to the strategy of hitting the sides of the Othello board, especially the second square from the corner (B line).

This position is strategically important, and hitting this spot early can give you control of the board.

Side B/B is the beginning of a game that requires delicate balance and deep strategy in the Othello situation.


Side C/C stroke

Side C/C hitting is a method of hitting the third square from the corner (C line) in the center of the side on the Othello board.

This move is considered to be an important strategy for controlling the board in the mid-game and influencing future developments.

Side C/C hitting is a strategic move that expands your influence toward the center of the board.


runaway cow

The runaway bull is one of Othello’s tactics, and refers to a style that pursues aggressive and unpredictable steps.

This tactic aims to confuse the opponent and throw him off balance.

The runaway bull is an aggressive and appealing tactic that creates unpredictable developments on the Othello board.



A box refers to an arrangement that creates a rectangular pattern on the Othello board.

This form provides a strategic advantage in certain situations and has the effect of restricting the opponent’s movement.

The box is like a strategic fortress that allows you to toy with your opponent by skillfully manipulating the board.


white line

White lines refer to the tactics and situations in Othello that make the white stones line up in a straight line.

This line is especially used to establish superiority on the board and is the basis for offensive development and defense.

The white line emphasizes white’s influence on the Othello board and is key to building a strategic advantage.




In Othello, the term “mountain” refers to the arrangement of stones in a particular shape, generally with the stones gradually increasing in height toward the center.

This placement may be used to dominate the board in certain tactical deployments.

The “mountain” seems to reproduce the majesty of the natural world on the board, and is a symbolic placement for aiming for strategic heights.



This is a standard stone created from diagonal cutting, and white is slightly advantageous.


extra hand

In Othello, a “free move” refers to a move that does not need to be made immediately on the current board, leaving strategic options for future developments.

This move is used to put pressure on the opponent or create a more advantageous situation.

The spare move is a tactician’s move, symbolizing Othello’s deep insight and foresight.



A “line” in Othello refers to the state in which the stones are lined up in a straight line on the board.

Whether or not you can overturn the stones on this line will greatly affect your tactical development.

The line is a fundamental element of Othello, and its control is the key to victory.


line through

“Line passing” refers to a tactic in Othello that allows you to turn over stones in one direction in succession.

By using this technique, it is possible to change a large amount of stones to your own color at once.

Line threading is a powerful method that can dramatically change the surface of a board in an instant.


cut the line

“Cut the line” refers to the tactic in Othello where you deliberately place your stones on the line to prevent your opponent from using the line to overturn many stones.

This action allows you to block your opponent’s attacks in advance.

Although the strategy of cutting the line is defensive, it is an important means of influencing the flow of the game.


consecutive hits

In Othello, “sequential strikes” refers to flipping multiple lines at the same time or in succession, which allows you to change a large number of stones to your color in one move.

This technique is especially effective in the late stages of the game and can be the difference between winning and losing.

A flurry of attacks provides an opportunity to identify strategic moments and turn the tide in one fell swoop.



$ 1,000,000

The expression “$1 million spare hand” is used, and the hand is said to be extremely valuable.

However, the specific details are unknown.



This is one of the time settings used in Yahoo Japan Othello several years ago.

“There is a waiting time of 1 minute, and each move increases the time by 1 second.”

Players have little time to think, and their early strength is put to the test.

There were other time settings such as 1/0 and 1/2, but the Yahoo Othello service has ended and it is difficult to play with these time settings.



This is a time setting that was also used in Yahoo Japan Othello, and means “1 minute waiting time only.”

Since there is no increase in time, it is easy to run out of time if you stop moving, requiring faster judgment and abundant early power.

In the past, this rule was proposed as a countermeasure against soft hitting. Soft hitting tends to be sensitive to extremely short time settings.

The 1 minute rule is a rule that can be set not only in the former Yahoo Othello, but also in Play OK and Othello Quest.


Lasts for 20 minutes

This is the time limit used in regular Othello tournaments, and is used in most tournaments in Japan.

There may be a 30 minute time limit for world championships and a 40 minute time limit for tournament finals (confirmation required).


7th grade

Grade 7 is the lowest rank recognized by the Othello Federation.

However, in tournaments limited to junior high school students and below, and tournaments limited to elementary school students and below, even one win may result in a higher rank than usual.

However, there are some tournaments in which a total loss is recognized as grade 7. It is thought that there are very few holders of level 7, and even if they do, they are generally promoted quickly.


6th grade

This is the second lowest rank recognized by the Othello Federation.

Similar to 7th grade, you can advance to 5th grade with just one win, so it is thought that those who hold it will be promoted relatively quickly.


5th grade

You can get it by winning 1 or 2 in tournaments limited to players below grade level.

However, there are few people who maintain this rank, and it is common to be promoted after participating in a few tournaments.

There seem to be around 20 holders. Let’s do our best and get promoted!


4th grade

In tournaments limited to players below grade level, you can get it after about 2 to 3 wins.

In terms of Yahoo rating, you can get it if you have just been promoted to purple, or if you have a skill level of 1800 to 2000 (master to master) in Hangame.

In Othello Quest, you may be able to aim for it if you have a rate of 1500 to 1600.

At this rank, you have acquired basic skills and are starting to enjoy playing Othello, and with practice it is often possible to advance to the next level relatively quickly.

It is believed that around 30 people hold this rank. Let’s do our best and get promoted!


Level 3

In tournaments limited to players below grade level, you can get it by winning about 3 to 4 times in 6 to 7 rounds.

If you reach this rank, you will almost certainly be able to win against beginners. If this is your first time participating, this rank may be a good choice for you.

You can get it if you have a skill level of 1500-1600 on Yahoo, or around 2000 on Hangame (maintaining master).

In Othello Quest, you can aim for it if you have a rate of 1600 to 1700. Once you reach this rank, you may be considered a formidable opponent even in tournaments that are limited to players below this rank.


2nd class

In tournaments limited to players below grade level, you can get it by winning about 4 times in 6 to 7 rounds.

You can get it if you have the ability of 1600-1700 on Yahoo rate, and 2100-2300 (Meijin to Eisei Meijin) on Hangame.

In Othello Quest, you can aim for it if your rate is around 1700.

From this rank, he may be seen as a strong opponent even in tournaments limited to players below this rank.


1st class

In tournaments limited to players below grade level, you can get it by winning about 5 times in 6 to 7 rounds.

This rank is the highest, and the next rank is Shodan.

According to Yahoo rate, you can get it if you have an average score of 1700 or more, and if you have a skill level of 2200 to 2400 (Meijin to Eisei Master) in Hangame, you can get it.

For Othello Quest, the rate should be around 1750-1800. In 2007, a first-class player won the national open tournament, and went on to achieve good results at the world tournament.



In tournaments that are limited to Kyu-ranked players and beginners, you can generally earn Shodan rank by winning or winning 6 or more races.

If it’s an open tournament, aim for 4-5 wins out of 6 matches, or 5 wins out of 7 matches. In the OJG (Othello Junior Grand Prix), which is limited to elementary school students and younger, even a 3rd place winner will be certified as 1st Dan.

In addition, in order to obtain a rank of Shodan or higher, it is necessary to join the Japan Othello Federation, and an annual membership fee of 3,000 yen is required.

In addition, there is a certification fee of 1000 yen x the number of dans (a flat rate of 500 yen for all grades).

According to the Yahoo rating, if you can consistently maintain an orange rating (approximately 1800), you are considered to have enough ability to aim for 1st Dan.

In Hangame, it is considered possible to obtain it if you have a skill level of 2300 to 2500 (King or above). In Othello Quest, you can aim for it if your rating is around 1850-1900.

There are approximately 120 Shodan holders nationwide.

Although there is a part of 1st Dan that involves luck, I personally believe that open tournaments are sometimes easier to win than tournaments that are limited to 1st Dan and below.



In open tournaments, the goal is to win 5/6 or 5/7 from first place, and in tournaments limited to ranked players, you can get 5 to 6/7 wins or 4 to 5/6 wins.

A runner-up at OJG will be certified as 2-dan.

The difficulty level increases from the first stage, and a certain level of skill is required from the second stage.

Dan rank can also be an appealing point on your resume. The average rating for Yahoo rates is 1850 or higher, and Hangame’s average rating is 2400 or higher (King to God).

In Othello Quest, you can aim for it if your rating is around 1900-2000. There are approximately 100 2-dan holders nationwide.


3rd tier

In open tournaments, you can advance to 3rd dan, and in tournaments limited to dan players, you can win 6 out of 7 races or be runner-up.

You need to do well in local competitions. Winning the OJG is a condition for obtaining third-dan certification.

The difficulty level to obtain it has increased by one level, and you will need good results in the tournament.

The average rate for Yahoo rate is 1900 or more, and for Hangame it is 2500 or more (always divine).

In Othello Quest, you can aim for it if your rating is around 2000-2100. There are approximately 70 3-dan holders nationwide.

In order to advance from Shodan to Sandan, all dan holders must improve their abilities and demonstrate success in competitions.


Four steps

In order to be certified as 4th dan at a local tournament, the following conditions must be met.


National Tournament Block Preliminary
District Meijin Tournament
Special big tournament held about once a year

The goal is to win these competitions.

However, these tournaments are held infrequently, and the chances of obtaining 4-dan are very limited.

It is said that it is easier to qualify for national level tournaments than local ones, but that is if you can still participate.


Additionally, you will be certified as 4th dan based on your performance in the following competitions.

4/6 wins in the All Japan Open Division,
2nd place in the All Japan Women’s Division, 1st
place in the All Japan Free Division (however, the event may have ended recently), and
5/7 wins in the Championship Tournament.

If your Yahoo rating is around 2000, you may be ranked within the top 30 nationally.

In Othello Quest, if your rating is around 2100, you can aim for 4th tier.

The national average rate for 4-dan holders is about 1240, and there are about 60 people nationwide.


5th dan

It is said that it is extremely difficult to obtain a rank of 5-dan or higher, as it can only be recognized at national level competitions.

The conditions for winning are the results in the following competitions.


All-Japan Open Championship Open Championship Tournament
of All-Japan Masters

You can earn it by placing 4th to 8th in these tournaments.

In the women’s division, winning is a condition for recognition.

The national average rate for 5th dan holders is about 1280, and there are about 30 people nationwide.


6th dan

The condition for obtaining 6th dan is to achieve results in the following competitions.

All-Japan Open Championship Open Championship Tournament
of All-Japan Masters

If you come in runner-up or third place in these tournaments, you will be certified as Rokudan.

In the women’s division, 5-dan holders are further certified as 6-dan by winning the All-Japan or Meijin Tournament women’s division twice (as the Oza Tournament is open to the public, placing 4th to 8th in the 5-dan qualification criteria).

The national average rate for 6-dan holders is approximately 1360, and there are approximately 20 people nationwide.

When you reach 6th Dan, you may become famous in the Othello world.


Seventh dan

The condition for 7th dan is to win the following competitions.

All-Japan Open Championship Open Championship Tournament
of All-Japan Masters

The national average rate for 7th dan holders is approximately 1420, and there are currently 16 people with 7th dan.

You can only be promoted to 2nd dan in one tournament, but if you win the tournament mentioned above, you can be promoted to 7th dan all at once.

As a general rule, the certification fee is [1,000 yen x the rank obtained], but if you win, the 7th dan will be given to you by the federation, so there is no certification fee.


8th dan

Holders of 7th dan can also be certified as 8th dan by winning one of the following tournaments twice.

In reality, you need to have won a total of three times in these tournaments, and if you are promoted to 7th dan with 3 degrees under the 6th dan qualification standard, you can be promoted to 8th dan even if you win 2 times.

Simply put, to reach 8th dan or above, you need to win at least two of the above tournaments.

As of summer 2018, there are only two 8-dan holders. The average rate for the Othello Federation nationwide is 1546 (as of July 27, 2023).

Signature players of the Othello Federation, such as Mr. Njima, are currently 8th Dan.

By the way, it has a higher average rate and is more reliable than Kudan (because the number of N is smaller). There tends to be more holders of Kudan.



This is the highest tier recognized by the Othello Federation, and holders of 8th dan will be promoted to 9th dan by winning one of the following tournaments twice.

You must have won a total of 5 of these tournaments.

In addition, if you are promoted to 7th dan with 3 degrees under the 6th dan certification standard, you can be promoted to 9th dan even if you win 4 times.

There are currently only four 9-dan holders: Eiji Tamenori, Ken Murakami, Kazuhiro Sakaguchi, and Makoto Suekuni.

In 2009, Masaki Takizawa won the All Japan Championship and was promoted to 9th Dan. By the summer of 2018, Yusuke Takanashi and Kazuki Okamoto had been promoted, increasing the number of 9-dan holders to seven.


Honorary 10th Dan

This rank is held only by Goro Hasegawa, and cannot actually be obtained.


9 moves

This strategy is known as “9 moves”, and there is a procedure in which the situation can be concluded in as few as 9 moves and Black can win with 64 stones.

Famous progression steps include f5, d6, c5, f4, e3, f6, g5, e6, and e7.

However, this usually rarely occurs in actual games.

Despite appearances, it is said to occur very rarely.



“Fat” is a common progressive form derived from Torajoseki.

It is said that if both players continue to do their best, the game will end in a draw.

It is said that some high-level players memorize all 60 of these steps.



“Kurnik” is a website where you can play Othello, similar to Yahoo and Hangame.

Although these sites are not very large, they are known for attracting many world tournament participants and domestic dans.

Also, games using software are quickly detected here.

For example, if you activate anything other than the Othello game screen on your PC, the opponent’s ID will be dimmed.

There are ways to get around these measures, including adding the person to a blacklist.

Since “kurnik” is an overseas site, the notation is in English.

Recently, the number of “kurnik” players has decreased, and instead there is a site called “Play OK” written in Japanese, and many players seem to be using it.



“GL” is an abbreviation for “good luck” and is used at the start of a game.

If the other person is a foreigner, it would be a good idea to send this.



“gg” stands for “good game” and is used at the end of a game.




At the end


How did you like the Othello Reversi Glossary?


Please use this glossary to defeat your opponent in practice.


But Othello and Reversi are fun games.

When playing with friends at home instead of at a tournament

Don’t just win on your own, try to make your opponent enjoy it too.


So please enjoy Othello!


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