Remove late irreversible move extension

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 17ccab9251abb052a12c7e1b6a41ef8db75f5e4f..6ec4d80322372332e10f909a5c574dbf6be5f3d9 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1067,7 +1067,7 @@ moves_loop: // When in check, search starts from here
       // search of (alpha-s, beta-s), and just one fails high on (alpha, beta),
       // then that move is singular and should be extended. To verify this we do
       // a reduced search on all the other moves but the ttMove and if the
-      // result is lower than ttValue minus a margin then we will extend the ttMove.
+      // result is lower than ttValue minus a margin, then we will extend the ttMove.
       if (    depth >= 6
           &&  move == ttMove
           && !rootNode
@@ -1131,12 +1131,6 @@ moves_loop: // When in check, search starts from here
       if (type_of(move) == CASTLING)
           extension = 1;
 
-      // Late irreversible move extension
-      if (   move == ttMove
-          && pos.rule50_count() > 80
-          && (captureOrPromotion || type_of(movedPiece) == PAWN))
-          extension = 2;
-
       // Add extension to new depth
       newDepth += extension;