From 285bf7041ad214156188823eb9118e6af7f4b2e4 Mon Sep 17 00:00:00 2001 From: SFisGOD Date: Tue, 10 Nov 2020 18:28:43 +0100 Subject: [PATCH] Increase reduction at root when the best move does not change frequently STC: LLR: 2.94 (-2.94,2.94) {-0.25,1.25} Total: 51320 W: 5159 L: 4956 D: 41205 Ptnml(0-2): 215, 3897, 17242, 4082, 224 https://tests.stockfishchess.org/tests/view/5faa072367cbf42301d6a767 LTC: LLR: 2.98 (-2.94,2.94) {0.25,1.25} Total: 15952 W: 762 L: 642 D: 14548 Ptnml(0-2): 8, 561, 6725, 667, 15 https://tests.stockfishchess.org/tests/view/5faa4c3567cbf42301d6a794 closes https://github.com/official-stockfish/Stockfish/pull/3225 Bench: 3954692 --- AUTHORS | 2 +- src/search.cpp | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/AUTHORS b/AUTHORS index f0356090..f30be4de 100644 --- a/AUTHORS +++ b/AUTHORS @@ -86,7 +86,7 @@ Jekaa Jerry Donald Watson (jerrydonaldwatson) jjoshua2 Jonathan Calovski (Mysseno) -Jonathan Dumale (SFisGOD) +Jonathan Buladas Dumale (SFisGOD) Joost VandeVondele (vondele) Jörg Oster (joergoster) Joseph Ellis (jhellis3) diff --git a/src/search.cpp b/src/search.cpp index 56b56733..66ef5043 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1161,7 +1161,7 @@ moves_loop: // When in check, search starts from here if (thisThread->ttHitAverage > 509 * TtHitAverageResolution * TtHitAverageWindow / 1024) r--; - // Reduction if other threads are searching this position + // Increase reduction if other threads are searching this position if (th.marked()) r++; @@ -1169,7 +1169,8 @@ moves_loop: // When in check, search starts from here if (ss->ttPv) r -= 2; - if (!PvNode && depth > 10 && thisThread->bestMoveChanges <= 2) + // Increase reduction at root and non-PV nodes when the best move does not change frequently + if ((rootNode || !PvNode) && depth > 10 && thisThread->bestMoveChanges <= 2) r++; if (moveCountPruning && !formerPv) -- 2.39.2