From 6c1af710d16c6a358cc09c51a133120605c39e44 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ste=CC=81phane=20Nicolet?= Date: Wed, 20 May 2020 17:06:42 +0200 Subject: [PATCH] A combo of parameters tweaks MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch is a combinaison of two recent parameters tweaks which had failed narrowly (yellow) at long time control: • improvement in move ordering during search by softening the distinction between bad captures and good captures during move generation, leading to improved awareness of Stockfish of potential piece sacrifices (idea by Rahul Dsilva) • increase in the weight of pawns in the "initiative" part of the evaluation function. With this change Stockfish should have more incentive to exchange pawns when losing, and to keep pawns when winning. STC: LLR: 2.93 (-2.94,2.94) {-0.50,1.50} Total: 10704 W: 2178 L: 1974 D: 6552 Ptnml(0-2): 168, 1185, 2464, 1345, 190 https://tests.stockfishchess.org/tests/view/5ec5553b377121ac09e1023d LTC: LLR: 2.94 (-2.94,2.94) {0.25,1.75} Total: 60592 W: 7835 L: 7494 D: 45263 Ptnml(0-2): 430, 5514, 18086, 5817, 449 https://tests.stockfishchess.org/tests/view/5ec55ca2377121ac09e10249 Closes https://github.com/official-stockfish/Stockfish/pull/2691 Bench: 4519117 --- src/evaluate.cpp | 2 +- src/movepick.cpp | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index d04d724a..449cf6d7 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -730,7 +730,7 @@ namespace { // Compute the initiative bonus for the attacking side int complexity = 9 * pe->passed_count() - + 11 * pos.count() + + 12 * pos.count() + 9 * outflanking + 21 * pawnsOnBothFlanks + 24 * infiltration diff --git a/src/movepick.cpp b/src/movepick.cpp index b1e10587..e26f42ef 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -169,7 +169,7 @@ top: case GOOD_CAPTURE: if (select([&](){ - return pos.see_ge(*cur, Value(-55 * cur->value / 1024)) ? + return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ? // Move losing capture to endBadCaptures to be tried later true : (*endBadCaptures++ = *cur, false); })) return *(cur - 1); -- 2.39.2