After we have taken into account all cheap evaluation
terms, we check whether the score exceeds a given threshold.
If this is the case, we return a scaled down evaluation.
STC:
LLR: 3.35 (-2.94,2.94) [0.00,5.00]
Total: 12575 W: 2316 L: 2122 D: 8137
LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 67480 W: 9016 L: 8677 D: 49787
Current version is the one rewritten by ceebo
further edited by me.
Bench:
5367704
const int BishopCheck = 588;
const int KnightCheck = 924;
const int BishopCheck = 588;
const int KnightCheck = 924;
+ // Threshold for lazy evaluation
+ const Value LazyEval = Value(1500);
// eval_init() initializes king and attack bitboards for a given color
// adding pawn attacks. To be done at the beginning of the evaluation.
// eval_init() initializes king and attack bitboards for a given color
// adding pawn attacks. To be done at the beginning of the evaluation.
+
+ Value lazy_eval(Value mg, Value eg) {
+
+ if (mg > LazyEval && eg > LazyEval)
+ return LazyEval + ((mg + eg) / 2 - LazyEval) / 4;
+
+ else if (mg < -LazyEval && eg < -LazyEval)
+ return -LazyEval + ((mg + eg) / 2 + LazyEval) / 4;
+
+ return VALUE_ZERO;
+ }
+
ei.pi = Pawns::probe(pos);
score += ei.pi->pawns_score();
ei.pi = Pawns::probe(pos);
score += ei.pi->pawns_score();
+ // We have taken into account all cheap evaluation terms.
+ // If score exceeds a threshold return a lazy evaluation.
+ Value lazy = lazy_eval(mg_value(score), eg_value(score));
+ if (lazy)
+ return pos.side_to_move() == WHITE ? lazy : -lazy;
+
// Initialize attack and king safety bitboards
ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0;
ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.square<KING>(WHITE));
// Initialize attack and king safety bitboards
ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0;
ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.square<KING>(WHITE));