From a48573e15fbd18fecb087c9fc02c38a07cece68b Mon Sep 17 00:00:00 2001 From: Dubslow Date: Thu, 9 Mar 2023 18:33:13 -0600 Subject: [PATCH] More negative extensions on nonsingular nonpv nodes. Following up the previous gainer also in this nonsingular node section of code. Credit shared with @FauziAkram for realizing this nonsingular node stuff had some potential, and @XInTheDark for reminding us that !PvNodes better handle extensions/reductions than Pv. Passed STC: https://tests.stockfishchess.org/tests/view/640a7bb32644b62c339457c3 LLR: 2.95 (-2.94,2.94) <0.00,2.00> Total: 136776 W: 36598 L: 36149 D: 64029 Ptnml(0-2): 439, 14834, 37384, 15301, 430 Passed LTC: https://tests.stockfishchess.org/tests/view/640c43a02644b62c3394b23c LLR: 2.94 (-2.94,2.94) <0.50,2.50> Total: 79536 W: 21363 L: 20984 D: 37189 Ptnml(0-2): 28, 7525, 24285, 7900, 30 closes https://github.com/official-stockfish/Stockfish/pull/4441 Bench: 4444953 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index 349d4389..582e4457 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1104,7 +1104,7 @@ moves_loop: // When in check, search starts here // If the eval of ttMove is greater than beta, we reduce it (negative extension) else if (ttValue >= beta) - extension = -2; + extension = -2 - !PvNode; // If the eval of ttMove is less than value, we reduce it (negative extension) else if (ttValue <= value)