From: Vizvezdenec Date: Mon, 28 Sep 2020 17:20:06 +0000 (+0300) Subject: Adjust null move pruning constants X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=a5e68d9b25539b86304a9fb26afc616dc8126a1c;ds=sidebyside Adjust null move pruning constants Idea is that division by fraction of 2 is slightly faster than by other numbers so parameters are adjusted in a way that division in null move pruning depth reduction features dividing by 256 instead of dividing by 213. Other than this patch is almost non-functional - difference starts to exist by depth 133. passed STC https://tests.stockfishchess.org/tests/view/5f70dd943b22d6afa50693c5 LLR: 2.95 (-2.94,2.94) {-0.25,1.25} Total: 57048 W: 6616 L: 6392 D: 44040 Ptnml(0-2): 304, 4583, 18531, 4797, 309 passed LTC https://tests.stockfishchess.org/tests/view/5f7180db3b22d6afa506941f LLR: 2.95 (-2.94,2.94) {0.25,1.25} Total: 45960 W: 2419 L: 2229 D: 41312 Ptnml(0-2): 43, 1779, 19137, 1987, 34 closes https://github.com/official-stockfish/Stockfish/pull/3159 bench 3789924 --- diff --git a/src/search.cpp b/src/search.cpp index 4650b157..e5f286e4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -829,7 +829,7 @@ namespace { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and value - Depth R = (817 + 71 * depth) / 213 + std::min(int(eval - beta) / 192, 3); + Depth R = (982 + 85 * depth) / 256 + std::min(int(eval - beta) / 192, 3); ss->currentMove = MOVE_NULL; ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];