I’m really confused about how to calculate the value of endgame moves in Go. Could some of you experts help explain it, or recommend some clearer teaching materials?
The answer is 2, but I don’t understand why. My calculation:
Playing at A in this diagram yields White a point of territory. So, that is 1 points for White. If Black plays at A, Black gets 1 captured stones and 1 points of territory, so 2 points for Black. The difference between Black and White playing at A is 3 points.
Point swing calculations are hard. You are thinking about it the right way though, there is just one little catch.
1 point for a captured prisoner. That’s correct.
You are robbing White of 1 point of territory, that’s also correct
However, Black does not actually get any extra territory. Black stone at A will not be solidly connected to the rest of Black stones. Black will eventually “have to” fill in the empty space from the captured W stone to prevent the stone at A from being re-captured. Thus there will be no extra territory for B compared to the inital state.
Only the capture and the reduction of W territory are meant to be counted in this example.
The official answer is 3, mine is 2. My calculation:
Playing at A in this diagram yields White 2 point of territory. So, that is 2 points for White. If Black plays at A, Black gets nothing, so 0 points for Black. The difference between Black and White playing at A is 2 points.
The official answer is 4, mine is 5. My calculation:
If White plays at A in this diagram, White gets 3 point of territory. So, that is 3 points for White. If Black plays at A, Black gets 1 captured stones and 1 points of territory, so 2 points for Black. The difference between Black and White playing at A is 5 points.
The theory I refer to is the one provided by Online Go.
“You can calculate the value of a move in the endgame by comparing the number of points if White plays at a position with the number of points if Black plays there. The difference between Black playing there and White playing there is the value of the move. Playing at A in this diagram yields White a captured stone and a point of territory. So, that is 2 points for White. If Black plays at A, Black gets 2 captured stones and 2 points of territory, so 4 points for Black. The difference between Black and White playing at A is 6 points.”
Thank you for your reply. I’ve expanded on my question, as well as the source of the calculation method I referenced (OGS).
Regarding your explanation, though, I’m not sure whether this calculation needs to account for the subsequent N moves and their chain effects. My guess is that the teaching mechanism in OGS probably wouldn’t be designed to be too complex.
In each of your calculations you are missing the concept of a false eye. You have to connect there instead of getting a point of territory when your opponent is putting your stones in Atari from the outside. Maybe this helps: False Eye at Sensei's Library
If White plays at A, White gets 2 points of territory.
If Black plays at A, Black gets 0 points.
So the difference between Black and White playing at A is 2 + 0 = 2 points.
My guess is: White has to play at A1 to keep the territory at B1 if Black plays at A. Even though Black gets nothing, White loses 1 point of territory, so that is 1 point. So the difference becomes 2 + 1 = 3 points.
Is my reasoning correct?
No. It is about F1. If White plays at A2, White gets points at A1, B1 and F1.
If Black plays at A2, White looses the points at A1 and B1 and has to connect later at F1.
So White also looses the point at F1.
