Simplify Pv nodes related logic in LMR

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index f2e11e35b520ba4438e478b2a03b7feaaff03a7a..fabb0ff07ac7398404f33bcd432cfa47a24754d8 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1164,15 +1164,12 @@ moves_loop: // When in check, search starts here
       {
           Depth r = reduction(improving, depth, moveCount, rangeReduction > 2);
 
-          // Decrease reduction if on the PV (~2 Elo)
+          // Decrease reduction at some PvNodes (~2 Elo)
           if (   PvNode
-              && bestMoveCount <= 3)
+              && bestMoveCount <= 3
+              && beta - alpha >= thisThread->rootDelta / 4)
               r--;
 
-          // Increases reduction for PvNodes that have small window
-          if (PvNode && beta - alpha < thisThread->rootDelta / 4)
-              r++;
-
           // Decrease reduction if position is or has been on the PV
           // and node is not likely to fail low. (~3 Elo)
           if (   ss->ttPv