From b605103a34be5bea7815ab3f6d4a21d487d0182b Mon Sep 17 00:00:00 2001 From: Jerry Donald Watson Date: Tue, 13 Mar 2018 09:15:42 +0000 Subject: [PATCH] Simplify condition for ProbCut move count pruning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We retire depth-dependence in ProbCut move count pruning, the move count limit condition is now : "probCutCount < 3" STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 33895 W: 6995 L: 6897 D: 20003 http://tests.stockfishchess.org/tests/view/5aa6eaba0ebc59029781009d LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 28959 W: 4441 L: 4333 D: 20185 http://tests.stockfishchess.org/tests/view/5aa73dfa0ebc5902978100be Ideas for future work: • Is a flat move count limit in ProbCut ideal? Depth dependence, or dependence on some other variable, could possibly be reintroduced. • The move count limit 3 is untuned and a better value may exist. Closes https://github.com/official-stockfish/Stockfish/pull/1486 Bench: 5741807 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index b2622ab3..0f599fc2 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -766,7 +766,7 @@ namespace { int probCutCount = 0; while ( (move = mp.next_move()) != MOVE_NONE - && probCutCount < depth / ONE_PLY - 3) + && probCutCount < 3) if (pos.legal(move)) { probCutCount++; -- 2.39.2