Double PawnHistory size and update formula

Doubling PAWN_HISTORY_SIZE to 1024. So with that, we can apply a stronger learning signal.
The bonus/malus multipliers in the update_quiet_histories function have been increased accordingly.

Passed STC:
LLR: 2.97 (-2.94,2.94) <0.00,2.00>
Total: 111008 W: 29136 L: 28708 D: 53164
Ptnml(0-2): 367, 12870, 28609, 13284, 374
https://tests.stockfishchess.org/tests/view/68c201d659efc3c96b61117e

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 117210 W: 30142 L: 29664 D: 57404
Ptnml(0-2): 49, 12532, 32970, 13000, 54
https://tests.stockfishchess.org/tests/view/68c20a6259efc3c96b6111ef

closes https://github.com/official-stockfish/Stockfish/pull/6306

Bench: 2788334
This commit is contained in:
FauziAkram
2025-09-28 20:51:34 +02:00
committed by Joost VandeVondele
parent a47a1c1804
commit bbad001a49
2 changed files with 2 additions and 2 deletions
+1 -1
View File
@@ -33,7 +33,7 @@
namespace Stockfish {
constexpr int PAWN_HISTORY_SIZE = 512; // has to be a power of 2
constexpr int PAWN_HISTORY_SIZE = 1024; // has to be a power of 2
constexpr int CORRECTION_HISTORY_SIZE = 32768; // has to be a power of 2
constexpr int CORRECTION_HISTORY_LIMIT = 1024;
constexpr int LOW_PLY_HISTORY_SIZE = 5;
+1 -1
View File
@@ -1873,7 +1873,7 @@ void update_quiet_histories(
int pIndex = pawn_history_index(pos);
workerThread.pawnHistory[pIndex][pos.moved_piece(move)][move.to_sq()]
<< (bonus * (bonus > 0 ? 704 : 439) / 1024) + 70;
<< (bonus * (bonus > 0 ? 800 : 500) / 1024) + 70;
}
}