value of LMR and null-move
Posted: Mon Jul 12, 2010 5:47 pm
Thought it best to move this to a new topic since the old subject had nothing to do with this part of the discussion.
Here's current data from the tests I have running:
Now, what is what. First, I ran every test twice as I had been asked to "stress-test the A/C" since it has been having major problems. As a result, I ran each version twice, which is the -1 and -2 you see on the end of each name.
Crafty-23.0, Crafty-23.1 and Crafty-23.2 are the released versions to date. Crafty-23.3 is the current version that will be released in a couple of weeks. 23.3R01 has null-move disabled. 23.3R02 has LMR disabled. 23.3R03 has both null-move and LMR disabled.
Summary:
R03 is obviously the worst version, with an Elo of 2457 after 30,000 games. R02 has null-move on, LMR off, and shows a gain of +130 over the base version, which is the gain by adding null-move. R01 has LMR on, null-move off, and adds +185 Elo. You might expect the total gain to be the sum of those two, or +315. But they are, as I mentioned, complementary in how they operate, so the total gain is only +246.
This is larger than the last time I ran this. Not sure why. For LMR, I am not surprised that it has gone up some since this has been changed quite a bit since the last time I ran this test. I can't recall any changes to the null-move search to make it more effective. But apparently something has changed in the search or the eval that helps it. Or which has introduced a side-effect that null-move covers up effectively and removing it exposes the issue.
I am now starting a run with stockfish 1.6, which is what I have been using in all my tests. I have modified it to eliminate LMR while leaving everything else intact. I'll report the results when this finishes...
Here's current data from the tests I have running:
Code: Select all
Name Elo + - games score oppo. draws
Crafty-23.3-1 2704 3 3 30000 64% 2592 22%
Crafty-23.3-2 2703 3 3 30000 64% 2592 22%
Crafty-23.2-1 2656 3 3 30000 58% 2592 22%
Crafty-23.2-2 2652 3 3 30000 58% 2592 22%
Crafty-23.3R01-1 2643 3 3 30000 57% 2592 23%
Crafty-23.3R01-2 2641 3 3 30000 56% 2592 23%
Crafty-23.1-2 2637 3 3 30000 56% 2592 23%
Crafty-23.1-1 2632 3 3 30000 55% 2592 23%
Crafty-23.3R02-1 2587 3 3 30000 49% 2592 23%
Crafty-23.3R02-2 2586 3 3 30000 49% 2592 23%
Crafty-23.0-2 2543 3 3 30000 44% 2592 20%
Crafty-23.0-1 2543 3 3 30000 44% 2592 20%
Crafty-23.3R03-2 2457 4 4 30000 33% 2592 20%
Crafty-23.3R03-1 2457 4 4 30000 33% 2592 20%
Crafty-23.0, Crafty-23.1 and Crafty-23.2 are the released versions to date. Crafty-23.3 is the current version that will be released in a couple of weeks. 23.3R01 has null-move disabled. 23.3R02 has LMR disabled. 23.3R03 has both null-move and LMR disabled.
Summary:
R03 is obviously the worst version, with an Elo of 2457 after 30,000 games. R02 has null-move on, LMR off, and shows a gain of +130 over the base version, which is the gain by adding null-move. R01 has LMR on, null-move off, and adds +185 Elo. You might expect the total gain to be the sum of those two, or +315. But they are, as I mentioned, complementary in how they operate, so the total gain is only +246.
This is larger than the last time I ran this. Not sure why. For LMR, I am not surprised that it has gone up some since this has been changed quite a bit since the last time I ran this test. I can't recall any changes to the null-move search to make it more effective. But apparently something has changed in the search or the eval that helps it. Or which has introduced a side-effect that null-move covers up effectively and removing it exposes the issue.
I am now starting a run with stockfish 1.6, which is what I have been using in all my tests. I have modified it to eliminate LMR while leaving everything else intact. I'll report the results when this finishes...