X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=567f87660197e719cf83ab492191bd3d26945b30;hp=182d2d7f60493bc0069ec1bdc05ead0153609885;hb=07b5a28a68b4cc67f1447fce85fc910aa209b319;hpb=c33af32dada1be9f6aed851e8cf87599203e2eb2

diff --git a/src/search.cpp b/src/search.cpp
index 182d2d7f..567f8766 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -543,7 +543,7 @@ namespace {
     Depth extension, newDepth;
     Value bestValue, value, ttValue, eval;
     bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
-    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
+    bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture, pvExact;
     Piece movedPiece;
     int moveCount, quietCount;
 
@@ -813,6 +813,7 @@ moves_loop: // When in check search starts from here
                            &&  tte->depth() >= depth - 3 * ONE_PLY;
     skipQuiets = false;
     ttCapture = false;
+    pvExact = PvNode && ttHit && tte->bound() == BOUND_EXACT;
 
     // Step 11. Loop through moves
     // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
@@ -957,6 +958,10 @@ moves_loop: // When in check search starts from here
               if ((ss-1)->moveCount > 15)
                   r -= ONE_PLY;
 
+              // Decrease reduction for exact PV nodes
+              if (pvExact)
+                  r -= ONE_PLY;
+
               // Increase reduction if ttMove is a capture
               if (ttCapture)
                   r += ONE_PLY;