X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=b3dc2775175e4454913f247063294feddc1f14dc;hp=33ab6b5fdc71618407a16267ab342556ed63ca98;hb=4eca981e557704f4ce3db829adf380b8fc058926;hpb=5066e17eba4b9d4217a8d173de56e40e0e05fc6d;ds=sidebyside

diff --git a/src/search.cpp b/src/search.cpp
index 33ab6b5f..b3dc2775 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -894,6 +894,13 @@ moves_loop: // When in check search starts from here
               && moveCount >= FutilityMoveCounts[improving][depth])
               continue;
 
+          // History Score Pruning
+          if (   depth <= 3 * ONE_PLY
+              && thisThread->History[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO
+              && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
+                                    [pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO)
+              continue;
+
           predictedDepth = newDepth - reduction<PvNode>(improving, depth, moveCount);
 
           // Futility pruning: parent node