-/// MovePicker::score_captures(), MovePicker::score_noncaptures(),
-/// MovePicker::score_evasions() and MovePicker::score_qcaptures() assign a
-/// numerical move ordering score to each move in a move list. The moves
-/// with highest scores will be picked first by pick_move_from_list().
-
-void MovePicker::score_captures() {
- // Winning and equal captures in the main search are ordered by MVV/LVA.
- // 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 more 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.
- for (int i = 0; i < numOfMoves; i++)
- {
- int seeValue = pos.see(moves[i].move);
- if (seeValue >= 0)
- {
- if (move_promotion(moves[i].move))
- moves[i].score = QueenValueMidgame;
- else
- moves[i].score = int(pos.midgame_value_of_piece_on(move_to(moves[i].move)))
- -int(pos.type_of_piece_on(move_from(moves[i].move)));
- } else
- moves[i].score = seeValue;
- }
-}
-
-void MovePicker::score_noncaptures() {
- // First score by history, when no history is available then use
- // piece/square tables values. This seems to be better then a
- // random choice when we don't have an history for any move.
- Move m;\r
- int hs;\r
-\r
- for (int i = 0; i < numOfMoves; i++)\r
- {\r
- m = moves[i].move;\r
-\r
- if (m == killer1)\r
- hs = HistoryMax + 2;\r
- else if (m == killer2)\r
- hs = HistoryMax + 1;\r
- else\r
- hs = H.move_ordering_score(pos.piece_on(move_from(m)), m);\r
-\r
- // Ensure moves in history are always sorted as first\r
- if (hs > 0)\r
- hs += 1000;\r
-\r
- moves[i].score = hs + pos.mg_pst_delta(m);\r
- }
+/// score() assigns 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, preferring
+ // captures near our home rank. Surprisingly, this appears to perform slightly
+ // better than SEE-based move ordering: exchanging big pieces before capturing
+ // a hanging piece probably helps to reduce the subtree size.
+ // In the 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, saving some SEE calls in case we get a cutoff.
+ for (auto& m : *this)
+ m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - Value(200 * relative_rank(pos.side_to_move(), to_sq(m)));