From: Vizvezdenec Date: Tue, 18 May 2021 07:02:20 +0000 (+0300) Subject: Do more continuation history based pruning X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=d37de3cb1de63da5b2f8e6978c45c5b36973063b Do more continuation history based pruning This patch increases lmrDepth threshold for continuation history based pruning in search. This part of code for a long time was known to be really TC sensitive - decreasing this threshold easily passed lower time controls but failed badly at LTC, on the other hand it increase was part of a tuning that resulted in being negative at STC but was +12 elo at 180+1.8. After recent simplification of special conditions that sometimes increase it from 4 to 5 it was logical to overall test at longer time controls if 5 is better than 4 with deeper searches. reduces strenght on STC https://tests.stockfishchess.org/tests/view/60a3a8bbce8ea25a3ef03c74 ELO: -2.57 +-2.0 (95%) LOS: 0.6% Total: 20000 W: 1820 L: 1968 D: 16212 Ptnml(0-2): 68, 1582, 6836, 1458, 56 Passed LTC with STC bounds https://tests.stockfishchess.org/tests/view/60a027395085663412d090ce LLR: 2.93 (-2.94,2.94) <-0.50,2.50> Total: 175256 W: 6774 L: 6548 D: 161934 Ptnml(0-2): 91, 5808, 75604, 6034, 91 Passed VLTC with LTC bounds https://tests.stockfishchess.org/tests/view/60a2bccce229097940a037a7 LLR: 2.96 (-2.94,2.94) <0.50,3.50> Total: 65736 W: 1224 L: 1092 D: 63420 Ptnml(0-2): 5, 1012, 30706, 1136, 9 closes https://github.com/official-stockfish/Stockfish/pull/3473 bench 3689330 --- diff --git a/src/search.cpp b/src/search.cpp index ac026a79..8f8d42c0 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1025,7 +1025,7 @@ moves_loop: // When in check, search starts from here else { // Continuation history based pruning (~20 Elo) - if ( lmrDepth < 4 + if ( lmrDepth < 5 && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold) continue;