Set reduction to 0 if the move is a TT move

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 483412c598a870cf6d78bde0175109f5f505abf9..8b2cc572fe7308a392866cbf3f2b53454f5ff3fa 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1147,9 +1147,10 @@ moves_loop:  // When in check, search starts here
         if ((ss + 1)->cutoffCnt > 3)
             r++;
 
-        // Decrease reduction for first generated move (ttMove)
+        // Set reduction to 0 for first generated move (ttMove)
+        // Nullifies all previous reduction adjustments to ttMove and leaves only history to do them
         else if (move == ttMove)
-            r--;
+            r = 0;
 
         ss->statScore = 2 * thisThread->mainHistory[us][from_to(move)]
                       + (*contHist[0])[movedPiece][to_sq(move)]