Sente Nature

"Always sente"  

Black is a move that has very small point value, but carries a threat of a much larger follow-up.

If white would get to play at , white would have 5 points in the corner

If black plays , and white responds, white has 4 points, so preventing the move is worth one point.

If black plays and white does not immediately reply, black can kill the whole white group. This is worth 20 points.

Such a move is said to be sente against the white group, and because the threat is very big, the move is likely be sente even considering the whole board.

The sente nature is very strong in moves that are "always sente".

Sente nature (outside stones alive)  

here has a much smaller follow-up than the previous example, so it is not necessarily sente when the whole board is taken into account.

The follow-up (6 points) is, however, much bigger than the value of preventing (one point). This means that as the game progresses, white will find it difficult to justify taking just one point in gote, while at some point of the game the remaining endgame elsewhere on the board will be small enough that white will want to respond to by capturing the three stones.

In other words, because the threat is bigger than preventing the move, it is very likely that when the endgame is actually played, it is the sente move that will actually get played.

Such moves are said to have a sente nature. Other, more common ways to express this are, for example:

• is black's privilege (applies only when the difference is big enough)
• The endgame in this position is sente for black

has a sente nature, but is not sente  

If black now saves the three stones in the corner, black has actually ended up in gote.

"More sente"

If the opponent plays a move that carries an even bigger threat, then the move was not absolutely sente.

Mutual respect  

Borrowing the example from basic endgame theory, the play at clearly has a sente nature, but white's best play is to force before defending?.

In this kind of situations black will actually end up with sente, so might be called "sente, but not immediately so".