CMH Pruning Tweak

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index a487ed1305b1ccdc8aabe5b42858ec71799b5895..5aa506446c3f68ef7474e4ecd49709714926c622 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1018,9 +1018,10 @@ moves_loop: // When in check, search starts here
           else
           {
               // Continuation history based pruning (~20 Elo)
-              if (   lmrDepth < 5
-                  && (*contHist[0])[movedPiece][to_sq(move)] < 23 - 23 * depth * depth
-                  && (*contHist[1])[movedPiece][to_sq(move)] < 23 - 23 * depth * depth)
+              if (lmrDepth < 5
+                  && (*contHist[0])[movedPiece][to_sq(move)]
+                  + (*contHist[1])[movedPiece][to_sq(move)]
+                  + (*contHist[3])[movedPiece][to_sq(move)] < -3000 * depth + 3000)
                   continue;
 
               // Futility pruning: parent node (~5 Elo)