Singular quiet LMR

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 4747beb2e94b503f3df11d55fee058dae989757b..1e133447d381b547f97d9ea93ab7aa7321d862f7 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -630,7 +630,8 @@ namespace {
     Depth extension, newDepth;
     Value bestValue, value, ttValue, eval, maxValue;
     bool ttHit, ttPv, formerPv, givesCheck, improving, didLMR, priorCapture;
-    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture, singularLMR;
+    bool captureOrPromotion, doFullDepthSearch, moveCountPruning,
+         ttCapture, singularQuietLMR;
     Piece movedPiece;
     int moveCount, captureCount, quietCount;
 
@@ -971,7 +972,7 @@ moves_loop: // When in check, search starts from here
                                       depth > 12 ? ss->ply : MAX_PLY);
 
     value = bestValue;
-    singularLMR = moveCountPruning = false;
+    singularQuietLMR = moveCountPruning = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
 
     // Mark this node as being searched
@@ -1092,7 +1093,7 @@ moves_loop: // When in check, search starts from here
           if (value < singularBeta)
           {
               extension = 1;
-              singularLMR = true;
+              singularQuietLMR = !ttCapture;
           }
 
           // Multi-cut pruning
@@ -1198,7 +1199,7 @@ moves_loop: // When in check, search starts from here
               r--;
 
           // Decrease reduction if ttMove has been singularly extended (~3 Elo)
-          if (singularLMR)
+          if (singularQuietLMR)
               r -= 1 + formerPv;
 
           if (!captureOrPromotion)