Not to let the players think forever (and to let the organizers schedule the next rounds at Go tournaments), the time for a single game of Go might be limited by using a special clock.
How do the clocks for Go work?
The clocks work in a way that when you start the game, you launch the clock and it starts to count your time down. After you play your move on the board, you press a lever or a button on the clock. Then your opponent’s time is being counted down. After they play their move on the board, they press the clock. Then your time is being counted down again, etc.
If you fail to play your move before your time runs out, you lose the game.
For Go matches there are several major time controls to consider. Let’s check them one by one.
Most important time controls in Go
“Sudden death”
It’s the easiest to understand, popular in some other games, but pretty rare time control in Go.
In “sudden death” each player has a certain amount of time at the beginning of the game. And each player needs to play all their moves within this time limit.
Example: Each player has a time limit of 1h. And it doesn’t matter how many moves the game takes, a player needs to play all their moves within that 1h.
“Sudden death” is a very convenient time control for the organizers of Go tournaments to schedule the next rounds, because they know how long the games can take (if each player has a time limit of 1h, the game can take 2h at most).
However, this time setting might be very uncomfortable for the players. On the start of the game the players don’t know if their game is going to have 150 or 300 moves and it might be difficult for them to decide how much time they can spend for thinking at various points of the game.
Japanese byo-yomi
In the Far East (Japan, Korea, China) the Japanese byo-yomi is definitely the most popular time control in Go.
On the start of the game each player has a certain amount of “basic time” - it works same as the time limit in “sudden death”. However, after a player runs out of the basic time, instead of losing the game, an additional time limit per move starts to be used.
Example: Each player has a time limit of 1h basic time and 30s Japanese byo-yomi. It doesn’t matter if a player plays 1 or 100 moves within their basic time. At any case, after their basic time is over, this player can still continue their game with a 30s time limit per move. However, if then the player doesn’t play their move within that 30s limit, they lose their game.
Japanese byo-yomi is a convenient time control for the players. No matter how complicated a situation on the board is, a player knows that even if he/she spends more time for analyzing the situation, they are still going to have the byo-yomi to be able to finish their game.
However, it’s necessary to keep in mind, that it’s more difficult to play after entering byo-yomi, because since then you will not be able to spend much time for playing any single move... and it might also be impossible for you to e.g. visit a toilet.
Sometimes the Japanese byo-yomi can be played with more times, e.g. 3, 5, 10.
At the information of the tournament you will see then the time control written as e.g. 45min basic time + 3x20s or 30min main time + 10x10s or 1h+5x30s.
In such time control (1h+5x30s), after you run out of your 1h basic time, you will start to be limited with 30s per move. However, you will be able to exceed the 30s limit four times. You would lose the game only after exceeding the 30s limit the fifth time.
This way you will be able to decide whether you wish to think a bit longer in several more complicated situations.
If there are more rounds per day in a tournament, the Japanese byo-yomi makes scheduling more difficult, because it’s not so easy to estimate how long a round would take.
We don’t know how many moves will be played before the players enter byo-yomi. We don’t know how long the players will be playing their moves in byo-yomi - in some obvious situations it can take e.g. only 1s to play a move, in more complicated situations the players will be usually thinking as long as they can, e.g. 29s in 30s limit.
The next thing is that even though we know there are usually about 200-250 moves in a Go game, some games might consist of a bigger number of moves.
Canadian byo-yomi
This time control is almost unknown among the Far Eastern Go players, but it used to be quite popular in the West.
On Asian Go tournaments it’s unlikely to find any mechanical clocks. Instead, the digital clocks are being used there.
In Europe and America chess used to be a more popular game than Go and the chess mechanical clocks were cheaper and more easily accessible. Playing with Japanese byo-yomi on those clocks would be very inconvenient and a different time control started to gain popularity for Go matches played with mechanical clocks.
Same like with Japanese byo-yomi and any other kind of byo-yomi, in the beginning of the game each player has a certain amount of basic time. Then, if Canadian byo-yomi is used, after a player runs out of their basic time, an additional time limit per certain number of moves starts to be used.
Example: Each player has a time limit of 1h basic time and 10min for 25 moves byo-yomi. After the basic time of a player is over, they get additional 10min for playing their next 25 moves. Then, if the player doesn’t play all 25 moves within those 10min (and the game hasn’t ended yet), they lose by time. If a player plays all 25 moves within 10min, their time will be reset, so that again they will have 10min for playing another 25 moves.
At face-to-face tournaments the player who enters the Canadian byo-yomi, takes out from their gosu (container for stones) the number of stones needed to be played within the necessary period of time. And then they close their gosu and put it away.
At the same time their opponent stops the clock and sets the time limit for their opponent. Then the player entering byo-yomi checks if the clock is set well and the game goes on.
Canadian byo-yomi is pretty convenient for the players that they might be able to spend more time for playing some moves in more complicated situations. On the other hand the players need to take care of one extra thing, i.e. their time management.
The digital clocks (used for playing in Japanese byo-yomi) are created to signal when a player is running out of time (e.g. they beep or speak the last 10s countdown).
The mechanical clocks (used for playing in Canadian byo-yomi) usually don’t send any voice signals, so the players need to check how much time they have left.
The next problem is that on the mechanical clocks it might be not so easy for a player to see well how much time left, e.g. if they still have 1min left or maybe 5s only.
For organizers, if the Canadian byo-yomi is used instead of the Japanese byo-yomi, it should be a bit easier to estimate how long a round should take. Thus, the scheduling of the following games should be easier, too.
Fischer time
It’s a quite new time control, quickly gaining popularity on European Go tournaments.
In Fischer time each player starts the game with some basic time. However, before playing each of their moves, a player’s remaining time is incremented by a certain amount of additional time.
Example: Each player has a time limit of 1h basic time and 10s increment. At the beginning of the game the players see that the clock shows 01:00:10 for each player.
A player plays a move after 25s (00:59:45 is the remaining time before pressing the clock). However, while pressing the clock the player gets the increment of 10s for their next move, so the clock will show 00:59:55 then.
Fischer time seems quite convenient for players. Even if a player doesn’t have much time left, but he/she wants to think longer over a complicated situation, they can play e.g. a few sente moves in some other part of the board. This way they are able to gain some extra time, which they would use then to think over that complicated situation.
This time control seems quite convenient for organizers, too. An organizer can e.g. count how much time at most a game consisting of 300 moves would take, add 10 minutes for any delays before the start of the game, add another 10 minutes for counting points, cleaning, entering the last results to the pairing program and printing the pairing for the next round. And then, according to this information, an organizer can schedule the following rounds of the tournament.
It’s good to keep in mind that a round can take longer if more moves are played, so it’s possible to have some delays. However, delays or longer breaks between the rounds are less likely to happen while using Fischer time in comparison with Canadian or Japanese byo-yomi.
Progressive byo-yomi
The progressive byo-yomi is used on some “fun Go events” rather than on serious championships. It’s a time control less popular, but working quite similarly to the Canadian byo-yomi. It’s another time control dedicated for the mechanical clocks.
The difference between Canadian and progressive byo-yomi is that the player needs to play more moves in every following period of time.
Example: Each player has a time limit of 1h basic time and 5min for 15 moves progressive byo-yomi incremented by 5 moves. After the basic time of a player is over, they get additional 5min for playing their next 15 moves. If a player plays all 15 moves within 5min, their time will be reset, so that again they will have 5min, but for playing another 20 moves (instead of 15). In the next period they will have 5min for playing 25 moves, etc.
Rapid byo-yomi
This time control is sometimes being used in the Far East, but it’s almost unknown at the European and American Go tournaments.
There is no basic time in rapid byo-yomi. At the beginning of the game each player gets a certain number of times of Japanese byo-yomi. However, after a player exceeds one of the times, that time is deducted, but the amount of time for this very one move gets different than it would in the normal Japanese byo-yomi.
Example: Each player has a time limit of 10 times of 30s rapid byo-yomi moving up to 60s. If a player plays a move within 30s, they have 10 times left. If a player doesn’t play a move within 30s, they have 9 times left and the player has another 60s (instead of 30s) to play their next move. However, in their following turns, such a player will have again only 30s per move. If a player loses one more time, they will have 60s per their very next move again.
Rapid byo-yomi lets the players think a bit longer in more complicated situations, but anyway they will not be able to e.g. sacrifice a lot of time to solve a difficult tsumego.
Summarizing, each of the described time controls works a bit differently. Some might be easier to play with, some might be more difficult. However, it doesn’t mean that all the games should be played with the easiest time controls. The easier the time control the easier for both players, the more difficult the time control the more difficult for both players.
Fair play vs victory by time
Let’s say the game is almost over, there are no more points to get. The game is being played with "sudden death" or Canadian byo-yomi. You know that your opponent has more points than you, but they only have a few seconds left. What do you do?
According to the “fair play behaviour” you should say “pass” in your next turn, count the points, and lose the game.
On the other hand, you could decide to play some stupid moves, e.g. ko threats. Your opponent will need to answer on these kind of moves, and even though you’re losing by points, you will win by time.
Almost none of the top players wants to lose their face, so they would rather decide to “pass” and lose their game (and sometimes a very big prize money, too). But it’s possible not to play fair and win such a game. And it would not be cheating, it would be a “legal” victory. The question is what is more valuable for such a player - a good reputation or a victory in that single game?
How to set a Go clock?
When you already know how the most popular time controls work, you can also check below our tutorial about how to set a clock for your Go match.
