LMR reduction parameter tweak

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index f0ee1b2b90f628c389627c29a989c98936017322..d03a251fe2d3516a9130868fb3073cce7aee8792 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1010,7 +1010,7 @@ moves_loop: // When in check search starts from here
 
           // Increase reduction for cut nodes
           if (!PvNode && cutNode)
-              r += ONE_PLY;
+              r += 2 * ONE_PLY;
 
           // Decrease reduction for moves that escape a capture. Filter out
           // castling moves, because they are coded as "king captures rook" and
@@ -1019,7 +1019,7 @@ moves_loop: // When in check search starts from here
           else if (   type_of(move) == NORMAL
                    && type_of(pos.piece_on(to_sq(move))) != PAWN
                    && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO)
-              r -= ONE_PLY;
+              r -= 2 * ONE_PLY;
 
           // Decrease/increase reduction for moves with a good/bad history
           int rHist = (val - 10000) / 20000;