Adjust NNUE usage based on number of pawns in position
authorVizvezdenec <Vizvezdenec@gmail.com>
Sun, 9 Aug 2020 18:39:46 +0000 (21:39 +0300)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Sun, 9 Aug 2020 19:26:17 +0000 (21:26 +0200)
commit2bfde5542919c2ed624b5b62883616e325ccb942
tree75ed0535b707c2ada48e4e56ae350fd42822c696
parentcd1bb27dd452f336d434a45131bfbe43f8a8c5b3
Adjust NNUE usage based on number of pawns in position

The idea of this patch is that positions are usually more complex and hard to evaluate even if there are more pawns.
This patch adjusts NNUE threshold usage depending on number of pawns in position, if pawn count is <3 we use the
classical evaluation more often, for pawn count = 3 patch the is non-functional,
with pawn count > 3 NNUE evaluation is used more often.

passed STC
https://tests.stockfishchess.org/tests/view/5f2f02d09081672066536b1f
LLR: 2.96 (-2.94,2.94) {-0.50,1.50}
Total: 36520 W: 5011 L: 4823 D: 26686
Ptnml(0-2): 299, 3482, 10548, 3594, 337

passed LTC
https://tests.stockfishchess.org/tests/view/5f2f4c329081672066536b5c
LLR: 2.98 (-2.94,2.94) {0.25,1.75}
Total: 39272 W: 2630 L: 2433 D: 34209
Ptnml(0-2): 53, 2066, 15218, 2229, 70

closes https://github.com/official-stockfish/Stockfish/pull/2960

bench 4084753
src/evaluate.cpp