Give extra bonus to main history for moves that caused a fail low. #4744

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 24f54c32bb35537231576690f35e4bb479f70667..ce9ed9508aa2e03af4af54c7740225211c8baf11 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1373,6 +1373,7 @@ moves_loop: // When in check, search starts here
     {
         int bonus = (depth > 5) + (PvNode || cutNode) + (bestValue < alpha - 113 * depth) + ((ss-1)->moveCount > 12);
         update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * bonus);
+        thisThread->mainHistory[~us][from_to((ss-1)->currentMove)] << stat_bonus(depth) * bonus / 2;
     }
 
     if (PvNode)