mirror of
https://github.com/sockspls/badfish
synced 2025-05-02 09:39:36 +00:00
af750bd2ef
Instead of current code, give a bonus according to the frontmost square among candidate + passed pawns. This is a big simplification that removes a lot of accurate code substituting it with a statistically based one using the common 'bonus' scheme, leaving to the search to sort out the details. Results are equivalent but code is much less and, as an added bonus, we now store candidates bitboard in pawns hash and allow this info to be used in evaluation. This paves the way to possible candidate pawns evaluations together with all the other pieces, as we do for passed. Patch passed short TC LLR: 2.96 (-2.94,2.94) [-1.50,4.50] Total: 16927 W: 3462 L: 3308 D: 10157 Then failed (quite quickly) at long TC LLR: -2.95 (-2.94,2.94) [0.00,6.00] Total: 8451 W: 1386 L: 1448 D: 5617 But when ran with a conclusive 40K fixed games at 60 secs it proved almost equivalent to original one. ELO: 1.08 +-2.0 (95%) LOS: 85.8% Total: 40000 W: 6739 L: 6615 D: 26646 bench: 3884003
80 lines
2.7 KiB
C++
80 lines
2.7 KiB
C++
/*
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
|
|
Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
|
|
|
|
Stockfish is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Stockfish is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef PAWNS_H_INCLUDED
|
|
#define PAWNS_H_INCLUDED
|
|
|
|
#include "misc.h"
|
|
#include "position.h"
|
|
#include "types.h"
|
|
|
|
namespace Pawns {
|
|
|
|
/// Pawns::Entry contains various information about a pawn structure. Currently,
|
|
/// it only includes a middle game and end game pawn structure evaluation, and a
|
|
/// bitboard of passed pawns. We may want to add further information in the future.
|
|
/// A lookup to the pawn hash table (performed by calling the probe function)
|
|
/// returns a pointer to an Entry object.
|
|
|
|
struct Entry {
|
|
|
|
Score pawns_value() const { return value; }
|
|
Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
|
|
Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
|
|
Bitboard candidate_pawns(Color c) const { return candidatePawns[c]; }
|
|
int pawns_on_same_color_squares(Color c, Square s) const { return pawnsOnSquares[c][!!(DarkSquares & s)]; }
|
|
int semiopen(Color c, File f) const { return semiopenFiles[c] & (1 << int(f)); }
|
|
int semiopen_on_side(Color c, File f, bool left) const {
|
|
|
|
return semiopenFiles[c] & (left ? ((1 << int(f)) - 1) : ~((1 << int(f+1)) - 1));
|
|
}
|
|
|
|
template<Color Us>
|
|
Score king_safety(const Position& pos, Square ksq) {
|
|
|
|
return kingSquares[Us] == ksq && castleRights[Us] == pos.can_castle(Us)
|
|
? kingSafety[Us] : update_safety<Us>(pos, ksq);
|
|
}
|
|
|
|
template<Color Us>
|
|
Score update_safety(const Position& pos, Square ksq);
|
|
|
|
template<Color Us>
|
|
Value shelter_storm(const Position& pos, Square ksq);
|
|
|
|
Key key;
|
|
Bitboard passedPawns[COLOR_NB];
|
|
Bitboard candidatePawns[COLOR_NB];
|
|
Bitboard pawnAttacks[COLOR_NB];
|
|
Square kingSquares[COLOR_NB];
|
|
int minKPdistance[COLOR_NB];
|
|
int castleRights[COLOR_NB];
|
|
Score value;
|
|
int semiopenFiles[COLOR_NB];
|
|
Score kingSafety[COLOR_NB];
|
|
int pawnsOnSquares[COLOR_NB][COLOR_NB];
|
|
};
|
|
|
|
typedef HashTable<Entry, 16384> Table;
|
|
|
|
Entry* probe(const Position& pos, Table& entries);
|
|
|
|
}
|
|
|
|
#endif // #ifndef PAWNS_H_INCLUDED
|