X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=d9b41cb35c4f87ee900106caf7ea0900962e239c;hb=440feecb4da2f051da6dafb70b4eb6cf443ccc1e;hp=d911593c03177f569afca9a9d6a6359750d42714;hpb=030b87182a7fff98b1724b857d6d40cda5d90b9f;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index d911593c..d9b41cb3 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1143,6 +1143,11 @@ moves_loop: // When in check, search starts here
       // Decrease reduction if ttMove has been singularly extended (~1 Elo)
       if (singularQuietLMR)
           r--;
+      
+      // Increase reduction on repetition (~1 Elo)
+      if (   move == (ss-4)->currentMove
+          && pos.has_repeated())
+          r += 2;
 
       // Increase reduction if next ply has a lot of fail high (~5 Elo)
       if ((ss+1)->cutoffCnt > 3)