Refine futility pruning for parent nodes
authorMichael Chaly <Vizvezdenec@gmail.com>
Sun, 28 Nov 2021 12:19:18 +0000 (15:19 +0300)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Sun, 28 Nov 2021 13:25:06 +0000 (14:25 +0100)
commitaf050e5eed43f2d360bc6d38a9d9ef64b6ce6ad8
treea8a5ae08c780fb442afa957ac0d56ad5ee1d61ef
parent8bb5a436b240d22e3e9729a1cd094169941afd7c
Refine futility pruning for parent nodes

This patch is a result of refining of tuning vondele did after
new net passed and some hand-made values adjustements - excluding
changes in other pruning heuristics and rounding value of history
divisor to the nearest power of 2.

With this patch futility pruning becomes more aggressive and
history influence on it is doubled again.

passed STC
https://tests.stockfishchess.org/tests/view/61a2c4c1a26505c2278c150d
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 33848 W: 8841 L: 8574 D: 16433
Ptnml(0-2): 100, 3745, 8988, 3970, 121

passed LTC
https://tests.stockfishchess.org/tests/view/61a327ffa26505c2278c26d9
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 22272 W: 5856 L: 5614 D: 10802
Ptnml(0-2): 12, 2230, 6412, 2468, 14

closes https://github.com/official-stockfish/Stockfish/pull/3814

bench 6302543
src/search.cpp