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Multiple lazy stages.

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An extension of the lazy eval idea: when the score is sufficiently large
we now skip more granular parts of the eval.

Inspired by an original patch by Moez Jellouli
https://tests.stockfishchess.org/tests/view/5f03b2a159f6f03532894529
Credit to him!

STC https://tests.stockfishchess.org/tests/view/5f0a862c59f6f03532894924
LLR: 2.95 (-2.94,2.94) {-0.50,1.50}
Total: 13504 W: 2684 L: 2472 D: 8348
Ptnml(0-2): 229, 1496, 3111, 1666, 250

LTC https://tests.stockfishchess.org/tests/view/5f0ac0e159f6f0353289495b
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 31312 W: 3926 L: 3677 D: 23709
Ptnml(0-2): 185, 2773, 9509, 2986, 203

closes https://github.com/official-stockfish/Stockfish/pull/2814

bench: 4541608
This commit is contained in:
mstembera 2020-07-12 13:58:00 -07:00 • committed by Joost VandeVondele
parent 6c197c3964
commit c3092c54bc
1 changed files with 17 additions and 8 deletions
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25
src/evaluate.cpp
View file

@ -74,7 +74,8 @@ using namespace Trace;
namespace {
// Threshold for lazy and space evaluation
constexpr Value LazyThreshold = Value(1400);
constexpr Value LazyThreshold1 = Value(1400);
constexpr Value LazyThreshold2 = Value(1300);
constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
@ -786,7 +787,7 @@ namespace {
&& pos.non_pawn_material(BLACK) == RookValueMg
&& pos.count<PAWN>(strongSide) - pos.count<PAWN>(~strongSide) <= 1
&& bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN))
&& (attackedBy[~strongSide][KING] & pos.pieces(~strongSide, PAWN)))
&& (attacks_bb<KING>(pos.square<KING>(~strongSide)) & pos.pieces(~strongSide, PAWN)))
sf = 36;
else if (pos.count<QUEEN>() == 1)
sf = 37 + 3 * (pos.count<QUEEN>(WHITE) == 1 ? pos.count<BISHOP>(BLACK) + pos.count<KNIGHT>(BLACK)
@ -837,9 +838,12 @@ namespace {
score += pe->pawn_score(WHITE) - pe->pawn_score(BLACK);
// Early exit if score is high
Value v = (mg_value(score) + eg_value(score)) / 2;
if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64)
return pos.side_to_move() == WHITE ? v : -v;
auto lazy_skip = [&](Value lazyThreshold) {
return abs(mg_value(score) + eg_value(score)) / 2 > lazyThreshold + pos.non_pawn_material() / 64;
};
if (lazy_skip(LazyThreshold1))
goto make_v;
// Main evaluation begins here
initialize<WHITE>();
@ -856,12 +860,17 @@ namespace {
// More complex interactions that require fully populated attack bitboards
score += king< WHITE>() - king< BLACK>()
+ threats<WHITE>() - threats<BLACK>()
+ passed< WHITE>() - passed< BLACK>()
+ passed< WHITE>() - passed< BLACK>();
if (lazy_skip(LazyThreshold2))
goto make_v;
score += threats<WHITE>() - threats<BLACK>()
+ space< WHITE>() - space< BLACK>();
make_v:
// Derive single value from mg and eg parts of score
v = winnable(score);
Value v = winnable(score);
// In case of tracing add all remaining individual evaluation terms
if (T)