From b7b6b4ba18bc9d291c2c2fd300c22a3e008dcbb2 Mon Sep 17 00:00:00 2001 From: Stefan Geschwentner Date: Tue, 7 Sep 2021 13:22:20 +0200 Subject: [PATCH] Further improve history updates Now even double history updates if a search failed low at an expected PV or CUT node. STC: LLR: 2.93 (-2.94,2.94) <-0.50,2.50> Total: 30736 W: 7891 L: 7674 D: 15171 Ptnml(0-2): 90, 3477, 8017, 3694, 90 https://tests.stockfishchess.org/tests/view/61364ae30cd98ab40c0c9da5 LTC: LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 73600 W: 18684 L: 18326 D: 36590 Ptnml(0-2): 41, 7734, 20899, 8078, 48 https://tests.stockfishchess.org/tests/view/6136940f0cd98ab40c0c9df3 closes https://github.com/official-stockfish/Stockfish/pull/3694 Bench: 6030657 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index 6affa510..ed5dd6c2 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1325,7 +1325,7 @@ moves_loop: // When in check, search starts here // Bonus for prior countermove that caused the fail low else if ( (depth >= 3 || PvNode) && !priorCapture) - update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth + (PvNode || cutNode))); + update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * (1 + (PvNode || cutNode))); if (PvNode) bestValue = std::min(bestValue, maxValue); -- 2.39.2