Adjust usage of history in futility pruning

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 12c89de457b187bc4898e3d9956a05a9d0b4bebb..8f9fa62c832150f7f5c02e3b38ee9354aee9399b 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1063,10 +1063,12 @@ moves_loop: // When in check, search starts here
                   && history < -3000 * depth + 3000)
                   continue;
 
+              history += thisThread->mainHistory[us][from_to(move)];                  
+
               // Futility pruning: parent node (~5 Elo)
               if (   !ss->inCheck
                   && lmrDepth < 8
-                  && ss->staticEval + 172 + 145 * lmrDepth + history / 256 <= alpha)
+                  && ss->staticEval + 172 + 145 * lmrDepth + history / 128 <= alpha)
                   continue;
 
               // Prune moves with negative SEE (~20 Elo)