From af050e5eed43f2d360bc6d38a9d9ef64b6ce6ad8 Mon Sep 17 00:00:00 2001 From: Michael Chaly Date: Sun, 28 Nov 2021 15:19:18 +0300 Subject: [PATCH] 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index 8f9fa62c..807d2614 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1068,7 +1068,7 @@ moves_loop: // When in check, search starts here // Futility pruning: parent node (~5 Elo) if ( !ss->inCheck && lmrDepth < 8 - && ss->staticEval + 172 + 145 * lmrDepth + history / 128 <= alpha) + && ss->staticEval + 142 + 139 * lmrDepth + history / 64 <= alpha) continue; // Prune moves with negative SEE (~20 Elo) -- 2.39.2