Protonspring had a successful functional simplification that removes the
PassedFile array using a simple linear equation.
Merge the additive term S(5, 10) of protonspring passed file simplification
(pull request https://github.com/official-stockfish/Stockfish/pull/2250)
into the PassedRank array. This harmless change has a different bench because
the candidate passer evaluation will always get less compared to #2250,
as we apply bonus = bonus /2.
Tested as a non-regression against #2250
Passed STC
http://tests.stockfishchess.org/tests/view/
5d33427e0ebc5925cf0e6fa2
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 81459 W: 18174 L: 18171 D: 45114
Passed LTC
http://tests.stockfishchess.org/tests/view/
5d335c8d0ebc5925cf0e731e
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 18525 W: 3176 L: 3052 D: 12297
Closes https://github.com/official-stockfish/Stockfish/pull/2250
Closes https://github.com/official-stockfish/Stockfish/pull/2251
Bench:
3859856
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
constexpr Score PassedRank[RANK_NB] = {
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
constexpr Score PassedRank[RANK_NB] = {
- S(0, 0), S(5, 18), S(12, 23), S(10, 31), S(57, 62), S(163, 167), S(271, 250)
- };
-
- // PassedFile[File] contains a bonus according to the file of a passed pawn
- constexpr Score PassedFile[FILE_NB] = {
- S( -1, 7), S( 0, 9), S(-9, -8), S(-30,-14),
- S(-30,-14), S(-9, -8), S( 0, 9), S( -1, 7)
+ S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260)
};
// Assorted bonuses and penalties
};
// Assorted bonuses and penalties
constexpr Score LongDiagonalBishop = S( 45, 0);
constexpr Score MinorBehindPawn = S( 18, 3);
constexpr Score Outpost = S( 18, 6);
constexpr Score LongDiagonalBishop = S( 45, 0);
constexpr Score MinorBehindPawn = S( 18, 3);
constexpr Score Outpost = S( 18, 6);
+ constexpr Score PassedFile = S( 11, 8);
constexpr Score PawnlessFlank = S( 17, 95);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score RookOnPawn = S( 10, 32);
constexpr Score PawnlessFlank = S( 17, 95);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score RookOnPawn = S( 10, 32);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
int r = relative_rank(Us, s);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
int r = relative_rank(Us, s);
Score bonus = PassedRank[r];
Score bonus = PassedRank[r];
|| (pos.pieces(PAWN) & (s + Up)))
bonus = bonus / 2;
|| (pos.pieces(PAWN) & (s + Up)))
bonus = bonus / 2;
- score += bonus + PassedFile[file_of(s)];
+ score += bonus - PassedFile * std::min(f, ~f);