From: Vizvezdenec <Vizvezdenec@gmail.com>
Date: Sat, 10 Jul 2021 21:09:15 +0000 (+0300)
Subject: Remove second futility pruning depth limit
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=dbd7f602d3c7622df294f87d7239b5aaf31f695f

Remove second futility pruning depth limit

This patch removes futility pruning lmrDepth limit for futility pruning at parent nodes.
Since it's already capped by margin that is a function of lmrDepth there is no need to extra cap it with lmrDepth.

passed STC
https://tests.stockfishchess.org/tests/view/60e9b5dfd1189bed71812777
LLR: 2.97 (-2.94,2.94) <-2.50,0.50>
Total: 14872 W: 1264 L: 1145 D: 12463
Ptnml(0-2): 37, 942, 5369, 1041, 47

passed LTC
https://tests.stockfishchess.org/tests/view/60e9c635d1189bed71812790
LLR: 2.96 (-2.94,2.94) <-2.50,0.50>
Total: 40336 W: 1280 L: 1225 D: 37831
Ptnml(0-2): 24, 1057, 17960, 1094, 33

closes https://github.com/official-stockfish/Stockfish/pull/3612

bench: 5064969
---

diff --git a/src/search.cpp b/src/search.cpp
index 008a60ed..3cf50eb5 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1021,8 +1021,7 @@ moves_loop: // When in check, search starts from here
                   continue;
 
               // Futility pruning: parent node (~5 Elo)
-              if (   lmrDepth < 7
-                  && !ss->inCheck
+              if (   !ss->inCheck
                   && ss->staticEval + 174 + 157 * lmrDepth <= alpha
                   &&  (*contHist[0])[movedPiece][to_sq(move)]
                     + (*contHist[1])[movedPiece][to_sq(move)]