Use less reduction for escaping moves

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index e10454b0d982c9e68df1e89ccafb7c05c73c7962..3428a764f1ad3116d765828a50a4e9a522e16804 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -69,6 +69,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist
 
   stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
           !(ttm && pos.pseudo_legal(ttm));
+  threatenedPieces = 0;
 }
 
 /// MovePicker constructor for quiescence search
@@ -106,21 +107,19 @@ void MovePicker::score() {
 
   static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
 
-  [[maybe_unused]] Bitboard threatened, threatenedByPawn, threatenedByMinor, threatenedByRook;
+  [[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook;
   if constexpr (Type == QUIETS)
   {
       Color us = pos.side_to_move();
-      // squares threatened by pawns
+
       threatenedByPawn  = pos.attacks_by<PAWN>(~us);
-      // squares threatened by minors or pawns
       threatenedByMinor = pos.attacks_by<KNIGHT>(~us) | pos.attacks_by<BISHOP>(~us) | threatenedByPawn;
-      // squares threatened by rooks, minors or pawns
       threatenedByRook  = pos.attacks_by<ROOK>(~us) | threatenedByMinor;
 
-      // pieces threatened by pieces of lesser material value
-      threatened =  (pos.pieces(us, QUEEN) & threatenedByRook)
-                  | (pos.pieces(us, ROOK)  & threatenedByMinor)
-                  | (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn);
+      // Pieces threatened by pieces of lesser material value
+      threatenedPieces = (pos.pieces(us, QUEEN) & threatenedByRook)
+                       | (pos.pieces(us, ROOK)  & threatenedByMinor)
+                       | (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn);
   }
 
   for (auto& m : *this)
@@ -134,7 +133,7 @@ void MovePicker::score() {
                    +     (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)]
                    +     (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
-                   +     (threatened & from_sq(m) ?
+                   +     (threatenedPieces & from_sq(m) ?
                            (type_of(pos.moved_piece(m)) == QUEEN && !(to_sq(m) & threatenedByRook)  ? 50000
                           : type_of(pos.moved_piece(m)) == ROOK  && !(to_sq(m) & threatenedByMinor) ? 25000
                           :                                         !(to_sq(m) & threatenedByPawn)  ? 15000