go_next_phase();
}
-MovePicker::MovePicker(const Position& p, Move ttm, const History& h, int threshold)
+MovePicker::MovePicker(const Position& p, Move ttm, const History& h, int parentCapture)
: pos(p), H(h) {
assert (!pos.in_check());
// In ProbCut we consider only captures better than parent's move
- captureThreshold = threshold;
+ captureThreshold = parentCapture;
phasePtr = ProbCutTable;
if ( ttm != MOVE_NONE
public:
MovePicker(const Position&, Move, Depth, const History&, SearchStack*, Value);
MovePicker(const Position&, Move, Depth, const History&);
- MovePicker(const Position&, Move, const History&, int threshold);
+ MovePicker(const Position&, Move, const History&, int parentCapture);
Move get_next_move();
private:
// Static exchange evaluation
int see(Move m) const;
int see_sign(Move m) const;
+ static int see_value(PieceType pt);
// Accessing hash keys
Key get_key() const;
return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(c, s));
}
+inline int Position::see_value(PieceType pt) {
+ return seeValues[pt];
+}
+
inline Key Position::get_key() const {
return st->key;
}
}
// Step 9. ProbCut (is omitted in PV nodes)
- // If we have a good capture that raises the score well above beta and a reduced
- // search confirms the score then we can (almost) safely prune the previous move.
+ // If we have a very good capture (i.e. SEE > seeValues[captured_piece_type])
+ // and a reduced search returns a value much above beta, we can (almost) safely
+ // prune the previous move.
if ( !PvNode
&& depth >= RazorDepth + ONE_PLY
&& !inCheck
assert(rdepth >= ONE_PLY);
- MovePicker mp(pos, ttMove, H, Max(rbeta - refinedValue, VALUE_ZERO));
+ MovePicker mp(pos, ttMove, H, Position::see_value(pos.captured_piece_type()));
pinned = pos.pinned_pieces(pos.side_to_move());
while ((move = mp.get_next_move()) != MOVE_NONE)