Following the discussion, I decided to read a bit more seriously the book "Yose" by Dai Junfu and Motoki Noguchi (by the way, the last names are Dai and Noguchi). In that book, their method of counting is different than Bill's. Let me first summarize their method. Suppose we are given a position with a possible move for each player.
If the position is gote for both players
1. Play out the sequence starting from Black until Black ends in gote.
1.a. If there is no followup, count the score (i.e. number of points for Black minus number of points for white).
1.b. If Black has a sente move after that ("privilege" of Black), continue the second sequence until the end and count the score.
1.c. If both Black and White have a continuation after that, play out the two possible sequences and calculate the average of the scores after each sequence.
2. Do the same as in 1. above, but for White instead of Black.
3. Subtract the numbers obtained in 1. and 2.
If the position is sente for one player and gote for the other (position called sente/reverse sente):
Do the same, but multiply by 2 the obtained number.
Remarks.
- Some positions are sente for both players, but are not evaluated, no quantitative criteria are given to decide when to play them.
- The term "sente" is not defined by Dai, so the player is supposed to guess if a move is sente or not. This is obvious in most cases.
- Dai's evaluation is less scientific than Bill's, but looks reasonably precise for practical purposes. In examples I examined, it corresponds roughly to Bill's (value of Black's move + value of White's move). I don't know if it's true in general, so if someone has an example where there is a large discrepancy between these two numbers I would be interested.
- I didn't talk about kos yet, and I am confused about that point but won't discuss that in this thread.
Here is a double gote example (from page 77 of the book).
If White plays first, then White plays at "a" and ends in gote, but later White has the privilege to play
so the final position is this:If Black plays first, then Black plays at "a" and ends in gote, but there are two followup diagrams. In the first one, Black captures 2 stones
In the second one, White connects.
The average between the last two diagrams is 4 points for Black. The difference between "White plays first" and "Black plays first" is 8 points. To conclude, Dai's evaluation of "a" is 8 points gote.
Here is a sente/reverse sente example.
The difference between the two diagrams is 9 points reverse sente, which is equivalent to 18 points gote.
My question will follow in the next post.
tenukis after the cut
.
with sente. Later B "a" - W "b" is sente, leaving Black with 6 pts. of territory minus 1 pt. for the captured stone = 5 pts.