Applying endgame principles in other phases of the game ?
Posted: Mon Oct 19, 2020 7:50 am
In the "How evaluate double sente moves ?" I try to explain (see viewtopic.php?p=260680#p260680) that AI (sorry to have use the french acronym IA) was probably able to use its knowledged of endgame principles through all phases in the game.
Let me try to explain this with an exemple. For strong players it will look quite obvious but I suspect it could be interesting for weaker amateurs (like me). BTW don't try to correct bad moves but only to take the idea.
Years ago I was explained that after the sequence
in this part of the game (I did not show the moves made in the bottom part of the board because it is not the point) the move 
becomes locally a very big point and the best one and, to prove this, my teacher showed me the two following diagrams:
black is to passive because after white 
black has gained nothing
black is here to greedy because after white 
again black has gained nothing.
Fine isn'it?
Now let's try to analyse these moves with endgame theory tools.
When the board is empty, the temperature is t=14 => when black plays first the resulting score of the game will be t/2 = 7 (komi?).
When black plays she gains 14 points by this move but it is now white to play and, assuming the temperature remains t=14 then the expected result of the game will be 14 - t/2 = 7. Everything is OK; all moves are correct.
Considering white is a good move worth 14 points we reach again a position at temperature near from 14 and it is the same for black 3 with an expected result of 7.
Now what about the situation after white ?
The situation above is quite different because now the point "a" appears bigger than usual. Let's assume that the temperature is now t = 17 (just an example for an easier discussion OC)
By taking this point black gains 17 points but the big point has disappeared and the temperature drops to return to t=14. The expected result for black is now 17 - t/2 = 10 points and eventually black wins the game by 10 poinnt instead of 7.
You have to conclude that the white move should be a mistake isn'it?.
Let's go further. Let's suppose white but consider white has enough compensation because another big point "b" (say 17 points) has been built somewhere in the bottom of the game.
What is the expected result of the game: black plays "a", white plays the miai point "b", the temperature drop to t=14 and the expected result for the game is 17 - 17 + t/2 = 7.
Here it becomes very interesting
Look at at following endgame
The points "a" and "b" are worth 2 points gote and look miai but ... black may begin by playing the move "c" (which is locally a loss) which is sente but change the miai situation in a tedomri one with only the point "b" as remaining point => eventualyy black gains one point.
What about such strategy in our fuseki?
Assume black is able to force the exchange
Locally it is a loss but here the point: the initial position was a miai situation (a big 17 points gote point "a" in the upper part of the board against a big 17 points gote point "a" in the bottom part of the board) but after sequence black keeps sente and the situation has become a tedomari one with only a big point "b" in the bottom part of the board.
As a consequence after the exchange followed by black "b" the expected score for the game becomes 0 + 17 - t/2 = 10 and blacks gains the game by 10 points instead of 7.
The conclusion is obvious but can lead to very strange moves:
1) in a tedomari situation you play simply the best gote point (OC after some urgent kikashi moves)
2) in a miai situation try to be creative: look for a sente sequence aiming at lowering the temperature of one big point (may be at the cost of a small local loss) and change the situation to a tedomari one.
That what tell us endgame principles!
Let me try to explain this with an exemple. For strong players it will look quite obvious but I suspect it could be interesting for weaker amateurs (like me). BTW don't try to correct bad moves but only to take the idea.
Years ago I was explained that after the sequence
in this part of the game (I did not show the moves made in the bottom part of the board because it is not the point) the move becomes locally a very big point and the best one and, to prove this, my teacher showed me the two following diagrams:black
is to passive because after white black has gained nothingblack
is here to greedy because after white again black has gained nothing.Fine isn'it?
Now let's try to analyse these moves with endgame theory tools.
When the board is empty, the temperature is t=14 => when black plays first the resulting score of the game will be t/2 = 7 (komi?).
When black plays
she gains 14 points by this move but it is now white to play and, assuming the temperature remains t=14 then the expected result of the game will be 14 - t/2 = 7. Everything is OK; all moves are correct.Considering white is a good move worth 14 points we reach again a position at temperature near from 14 and it is the same for black 3 with an expected result of 7.
Now what about the situation after white
?The situation above is quite different because now the point "a" appears bigger than usual. Let's assume that the temperature is now t = 17 (just an example for an easier discussion OC)
By taking this point black gains 17 points but the big point has disappeared and the temperature drops to return to t=14. The expected result for black is now 17 - t/2 = 10 points and eventually black wins the game by 10 poinnt instead of 7.
You have to conclude that the white move
should be a mistake isn'it?.Let's go further. Let's suppose white
but consider white has enough compensation because another big point "b" (say 17 points) has been built somewhere in the bottom of the game.What is the expected result of the game: black plays "a", white plays the miai point "b", the temperature drop to t=14 and the expected result for the game is 17 - 17 + t/2 = 7.
Here it becomes very interesting
Look at at following endgame
The points "a" and "b" are worth 2 points gote and look miai but ... black may begin by playing the move "c" (which is locally a loss) which is sente but change the miai situation in a tedomri one with only the point "b" as remaining point => eventualyy black gains one point.
What about such strategy in our fuseki?
Assume black is able to force the exchange
Locally it is a loss but here the point: the initial position was a miai situation (a big 17 points gote point "a" in the upper part of the board against a big 17 points gote point "a" in the bottom part of the board) but after sequence
black keeps sente and the situation has become a tedomari one with only a big point "b" in the bottom part of the board.As a consequence after the exchange
followed by black "b" the expected score for the game becomes 0 + 17 - t/2 = 10 and blacks gains the game by 10 points instead of 7.The conclusion is obvious but can lead to very strange moves:
1) in a tedomari situation you play simply the best gote point (OC after some urgent kikashi moves)
2) in a miai situation try to be creative: look for a sente sequence aiming at lowering the temperature of one big point (may be at the cost of a small local loss) and change the situation to a tedomari one.
That what tell us endgame principles!
you imagine black 
white 
. The result looks a success for black because now the influence of the two white stone in the bottom left corner is towards the wrong direction.