Update comments in LMR step

Stefano80 · IIvec · commit 98409ced956b · 2016-01-21T19:00:51.000+01:00
No functional change Resolves #564
diff --git a/src/search.cpp b/src/search.cpp
@@ -1005,7 +1005,9 @@ namespace {
               && 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
