// 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
+ // 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.
+ Move m;
+ int seeValue;
+
for (int i = 0; i < numOfMoves; i++)
{
- int seeValue = pos.see(moves[i].move);
+ m = moves[i].move;
+ seeValue = pos.see(m);
if (seeValue >= 0)
{
- if (move_promotion(moves[i].move))
+ if (move_promotion(m))
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)));
+ moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
+ -int(pos.type_of_piece_on(move_from(m)));
} else
moves[i].score = seeValue;
}
}
void MovePicker::score_noncaptures() {
-
- for (int i = 0; i < numOfMoves; i++)
- {
- Move m = moves[i].move;
- if (m == killer1)
- moves[i].score = HistoryMax + 2;
- else if (m == killer2)
- moves[i].score = HistoryMax + 1;
- else
- moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m);
+ // 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
}
}
moves[i].score = QueenValueMidgame;
else
moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
- -int(pos.midgame_value_of_piece_on(move_to(m))) / 64;
+ -int(pos.type_of_piece_on(move_from(m)));
}
}