X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=0cee3aa93d382b49d4d5c4566d5fb6980f359514;hp=3e9506d7ef9be8f257bd4a7e245e40bb6f1e60b0;hb=dcd8ce70941e9b8d5180eb43865bb9819e424c19;hpb=4d1220d672d5f0b9cf1b0908cd685d685f1a26eb

diff --git a/src/search.cpp b/src/search.cpp
index 3e9506d7..0cee3aa9 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1005,7 +1005,9 @@ moves_loop: // When in check search starts from here
               && cmh[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO)
               r = std::max(DEPTH_ZERO, r - ONE_PLY);
 
-          // Decrease reduction for moves that escape a capture
+          // Decrease reduction for moves that escape a capture. Filter out castling
+          // moves because are coded as "king captures rook" and break make_move().
+          // Also use see() instead of see_sign() because destination square is empty.
           if (   r
               && type_of(move) == NORMAL
               && type_of(pos.piece_on(to_sq(move))) != PAWN