no cut node reduction for killer moves.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 62f02d835bfb192e2522d43b2ed02bf0a5304388..5974cba731ef04a6c71885216e92818392aa5c8d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -152,7 +152,7 @@ namespace {
 void Search::init() {
 
   for (int i = 1; i < MAX_MOVES; ++i)
-      Reductions[i] = int(21.3 * std::log(i + 0.25 * std::log(i)));
+      Reductions[i] = int(21.9 * std::log(i));
 }
 
 
@@ -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)
           {