Refine futility pruning for parent nodes

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 8f9fa62c832150f7f5c02e3b38ee9354aee9399b..807d261472fc091b96f7aaf71ec46c784a1f810a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1068,7 +1068,7 @@ moves_loop: // When in check, search starts here
               // Futility pruning: parent node (~5 Elo)
               if (   !ss->inCheck
                   && lmrDepth < 8
-                  && ss->staticEval + 172 + 145 * lmrDepth + history / 128 <= alpha)
+                  && ss->staticEval + 142 + 139 * lmrDepth + history / 64 <= alpha)
                   continue;
 
               // Prune moves with negative SEE (~20 Elo)