From 8bab09749dd00951bfa9c5f89f6e35bded76c8a9 Mon Sep 17 00:00:00 2001 From: FauziAkram Date: Mon, 3 Oct 2022 17:45:05 +0300 Subject: [PATCH] Mix alpha and statScore for reduction Idea by @xoto10, and tuning by @FauziAkram. Passed STC: LLR: 2.94 (-2.94,2.94) <0.00,2.00> Total: 57832 W: 15540 L: 15199 D: 27093 Ptnml(0-2): 207, 6343, 15477, 6680, 209 https://tests.stockfishchess.org/tests/view/6338db6f35f43d649ff60fdc passed LTC: LLR: 2.95 (-2.94,2.94) <0.50,2.50> Total: 50968 W: 13770 L: 13440 D: 23758 Ptnml(0-2): 25, 4905, 15306, 5211, 37 https://tests.stockfishchess.org/tests/view/6339777035f43d649ff62686 Links to the tuning sessions: https://tests.stockfishchess.org/tests/view/63345725a004bed9a2e47b28 https://tests.stockfishchess.org/tests/view/63345728a004bed9a2e47b2a closes https://github.com/official-stockfish/Stockfish/pull/4183 Bench: 4426602 --- src/search.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 4b6b497a..46463b32 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -787,9 +787,9 @@ namespace { // The depth condition is important for mate finding. if ( !ss->ttPv && depth < 8 - && eval - futility_margin(depth, improving) - (ss-1)->statScore / 303 >= beta + && eval - futility_margin(depth, improving) - (ss-1)->statScore / 301 >= beta && eval >= beta - && eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins + && eval < 28692) // larger than VALUE_KNOWN_WIN, but smaller than TB wins return eval; // Step 9. Null move search with verification search (~22 Elo) @@ -1179,7 +1179,7 @@ moves_loop: // When in check, search starts here - 4433; // Decrease/increase reduction for moves with a good/bad history (~30 Elo) - r -= ss->statScore / 13628; + r -= (ss->statScore + 5 * alpha) / 15448; // In general we want to cap the LMR depth search at newDepth, but when // reduction is negative, we allow this move a limited search extension -- 2.39.2