Sente
Sente is a Japanese Go term adopted into English. (Similar to "with tempo" in chess terms.)
The root meaning of sente is playing first.
The following are derived meanings:
- A player can have sente.
- A player can take sente.
- A move can be sente.
- A position can be sente for a player.
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A player having sente
A player has sente if it is their turn. (In particular, when they do not have to answer their opponent's last move.) Thus, a player who has sente can decide where to play next.
A player taking sente: playing first locally
Just as the base meaning of sente is playing first, a derived meaning is playing first in a local position. Thus, a player may avoid a local reply to the opponent's last move and take sente to play first elsewhere.
A sente move
A move is sente if the opponent has to answer it, so the player who plays it will have sente after the exchange. For example:
In this position Black can play in sente, because White has to answer to avoid dying. Not to have sente is to be constrained into a direct answer to your opponent's previous play. This state of affairs is called gote: having gote, taking or accepting gote.
( is worth 15 points locally in deiri counting. If there are larger plays on the board, White will ignore the threat and choose one of the larger plays. Exactly speaking, a sente move can be defined as "a move whose follow-up play is the largest on the board". Therefore, whether a move is sente or not changes many times during the game, depending on what's happening in other areas.)
We also, particularly in the endgame, describe a move as being
- reverse sente if it prevents an opponent making a sente move but (usually) is itself gote,
- double sente if it is sente and prevents an opponent making a sente move,
- double gote if neither it nor the opponent’s move is sente.
A sente position
A position is sente for a player if one may expect them to get to play there first.
This position is sente for Black. [1] After Black a, he has a follow-up play at b, saving two stones (worth 4 points). On the other hand, White's play at a has no follow-up plays. Therefore we expect Black to be able to play first in this position with sente, at some point in the endgame (more exactly, when the largest play on the board is worth less than 4 points and therefore White's reply at b is the best play for her). We say that Black has the privilege of playing first in this position.
Especially in the endgame, a position may also be described as sente, reverse sente or gote for a player if a move there is that for them. A position may also be called double sente or double gote in the obvious senses.
Patrick Traill: Are these usages perhaps discouraged, deprecated, disparaged or despised? In The Endgame (the book) they certainly apply the terminology to situations, which seems to mean the same as positions. Please someone update the paragraph to reflect observed usage and educated opinion and remove this annotation.
Sente in the endgame
As noted above, in the endgame the classification into (one-sided) sente, reverse sente, double sente or gote (i.e. double gote) is much used. In particular, a local sente position often refers to one player having a sente move and the opponent having a gote move. This classification is important to determine the correct priority of plays.
See also
- Value Of Sente
- Gote
- Sente nature
- Sente position
- Life in sente
- Reverse sente
- Getting sente - path
- Losing sente example
- Sente gains nothing
- Double sente
- Double sente is relative
- How big is the 6 point double sente
- Double sente gain discussion
- Ambiguous Move (does not change local temperature)
- Ambiguous position (neither sente nor gote, or perhaps either)
- Mutual Damage
[1] Robert Pauli: Another way to check that is to take four copies of this position and let Black start. If White always answers, she collects 4*4 = 16 points. If not, only 0 + 4 + 5 + 5 = 14 are hers. To broaden the picture, replace the black pair with respectively + (an empty intersection)
+ : | Black's threat still is sente | (4*3 > 0 + 3 + 4 + 4) |
: | Black's threat becomes ambiguous | (4*2 = 0 + 2 + 3 + 3) |
+: | Black's threat becomes gote | (4*1 < 0 + 1 + 2 + 2) |