From d5a36a3c92533782d6a74d16c080de0c1538f65d Mon Sep 17 00:00:00 2001 From: FauziAkram Date: Sat, 23 Nov 2024 14:37:08 +0300 Subject: [PATCH] Simplify probCutBeta formula After recent changes to the improving definition, seems like there is no need anymore to keep opponentWorsening in the probCutBeta formula. Passed STC: LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 214272 W: 55566 L: 55541 D: 103165 Ptnml(0-2): 620, 25540, 54817, 25513, 646 https://tests.stockfishchess.org/tests/view/6735243d86d5ee47d953eaea Passed LTC: LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 126708 W: 32329 L: 32216 D: 62163 Ptnml(0-2): 68, 13986, 35123, 14119, 58 https://tests.stockfishchess.org/tests/view/67393cf686d5ee47d953ef99 closes https://github.com/official-stockfish/Stockfish/pull/5697 Bench: 983067 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index ea43017e..5209bd07 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -855,7 +855,7 @@ Value Search::Worker::search( // Step 11. ProbCut (~10 Elo) // If we have a good enough capture (or queen promotion) and a reduced search // returns a value much above beta, we can (almost) safely prune the previous move. - probCutBeta = beta + 187 - 53 * improving - 27 * opponentWorsening; + probCutBeta = beta + 187 - 56 * improving; if (!PvNode && depth > 3 && !is_decisive(beta) // If value from transposition table is lower than probCutBeta, don't attempt