- stage = PROBCUT;
-
- // In ProbCut we generate only captures that are better than the parent's
- // captured piece.
- captureThreshold = PieceValue[MG][pt];
- ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
-
- if (ttMove && (!pos.capture(ttMove) || pos.see(ttMove) <= captureThreshold))
- ttMove = MOVE_NONE;
-
- endMoves += (ttMove != MOVE_NONE);
-}
-
-
-/// score() assign a numerical value to each move in a move list. The moves with
-/// highest values will be picked first.
-template<>
-void MovePicker::score<CAPTURES>() {
- // Winning and equal captures in the main search are ordered by MVV.
- // Suprisingly, this appears to perform slightly better than SEE based
- // move ordering. The reason is probably that in a position with a winning
- // capture, capturing a valuable (but sufficiently defended) piece
- // first usually doesn't hurt. The opponent will have to recapture, and
- // the hanging piece will still be hanging (except in the unusual cases
- // where it is possible to recapture with the hanging piece). Exchanging
- // big pieces before capturing a hanging piece probably helps to reduce
- // the subtree size.
- // In main search we want to push captures with negative SEE values to the
- // badCaptures[] array, but instead of doing it now we delay until the move
- // has been picked up in pick_move_from_list(). This way we save some SEE
- // calls in case we get a cutoff.
- for (auto& m : *this)
- m.value = Value(int(pos.piece_on(to_sq(m))));
+ stage = PROBCUT_TT;
+ ttMove = ttm
+ && pos.pseudo_legal(ttm)
+ && pos.capture(ttm)
+ && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
+ stage += (ttMove == MOVE_NONE);