no cut node reduction for killer moves.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index a413bd3814fec6daa13b08ed3bbe9db6182158b3..5974cba731ef04a6c71885216e92818392aa5c8d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1157,8 +1157,8 @@ moves_loop: // When in check, search starts from here
               r--;
 
           // Increase reduction for cut nodes (~3 Elo)
-          if (cutNode)
-              r += 1 + !captureOrPromotion;
+          if (cutNode && move != ss->killers[0])
+              r += 2;
 
           if (!captureOrPromotion)
           {