From 3747a1993722bfb9d5e7c784b2225e5aa742276f Mon Sep 17 00:00:00 2001 From: Daniel Monroe Date: Sun, 25 May 2025 12:32:32 -0700 Subject: [PATCH] Simplify away depth condition in IIR Passed simplification STC LLR: 2.94 (-2.94,2.94) <-1.75,0.25> Total: 359520 W: 92714 L: 92849 D: 173957 Ptnml(0-2): 977, 42640, 92614, 42599, 930 https://tests.stockfishchess.org/tests/view/6833705d6ec7634154f9c302 Passed simplification LTC LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 201756 W: 51544 L: 51507 D: 98705 Ptnml(0-2): 89, 21965, 56728, 22012, 84 https://tests.stockfishchess.org/tests/view/68338e386ec7634154f9c790 Passed simplification VLTC LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 48558 W: 12675 L: 12492 D: 23391 Ptnml(0-2): 9, 4779, 14516, 4970, 5 https://tests.stockfishchess.org/tests/view/6838e0b26ec7634154f9d25b closes https://github.com/official-stockfish/Stockfish/pull/6112 Bench: 2302583 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index f7390bc2c..b686808f3 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -896,7 +896,7 @@ Value Search::Worker::search( // Step 10. Internal iterative reductions // For PV nodes without a ttMove as well as for deep enough cutNodes, we decrease depth. // (*Scaler) Especially if they make IIR less aggressive. - if (!allNode && depth >= (PvNode ? 5 : 7) && !ttData.move) + if (!allNode && depth >= 6 && !ttData.move) depth--; // Step 11. ProbCut