2008-08-31 23:59:13 -06:00
|
|
|
/*
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
|
|
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
|
2016-01-02 02:43:25 -07:00
|
|
|
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
|
2018-01-01 02:33:07 -07:00
|
|
|
Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish is free software: you can redistribute it and/or modify
|
2008-08-31 23:59:13 -06:00
|
|
|
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.
|
2008-09-23 16:32:53 -06:00
|
|
|
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish is distributed in the hope that it will be useful,
|
2008-08-31 23:59:13 -06:00
|
|
|
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.
|
2008-09-23 16:32:53 -06:00
|
|
|
|
2008-08-31 23:59:13 -06:00
|
|
|
You should have received a copy of the GNU General Public License
|
|
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
*/
|
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
#include <algorithm> // For std::min
|
2008-08-31 23:59:13 -06:00
|
|
|
#include <cassert>
|
2014-12-30 02:31:50 -07:00
|
|
|
#include <cstring> // For std::memset
|
2008-08-31 23:59:13 -06:00
|
|
|
|
|
|
|
#include "material.h"
|
2014-12-30 02:31:50 -07:00
|
|
|
#include "thread.h"
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2009-07-26 10:42:48 -06:00
|
|
|
using namespace std;
|
2008-08-31 23:59:13 -06:00
|
|
|
|
|
|
|
namespace {
|
|
|
|
|
2014-12-27 02:47:21 -07:00
|
|
|
// Polynomial material imbalance parameters
|
2009-11-15 01:35:22 -07:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
const int QuadraticOurs[][PIECE_TYPE_NB] = {
|
2014-05-10 00:18:09 -06:00
|
|
|
// OUR PIECES
|
2013-03-13 17:23:29 -06:00
|
|
|
// pair pawn knight bishop rook queen
|
2016-08-30 12:15:51 -06:00
|
|
|
{1667 }, // Bishop pair
|
2017-03-17 15:41:08 -06:00
|
|
|
{ 40, 0 }, // Pawn
|
2015-10-20 20:46:06 -06:00
|
|
|
{ 32, 255, -3 }, // Knight OUR PIECES
|
|
|
|
{ 0, 104, 4, 0 }, // Bishop
|
|
|
|
{ -26, -2, 47, 105, -149 }, // Rook
|
2017-12-01 15:02:45 -07:00
|
|
|
{-189, 24, 117, 133, -134, -10 } // Queen
|
2013-03-13 17:23:29 -06:00
|
|
|
};
|
2009-07-20 02:56:21 -06:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
const int QuadraticTheirs[][PIECE_TYPE_NB] = {
|
2013-03-13 17:23:29 -06:00
|
|
|
// THEIR PIECES
|
|
|
|
// pair pawn knight bishop rook queen
|
2013-11-04 05:44:42 -07:00
|
|
|
{ 0 }, // Bishop pair
|
2015-10-20 20:46:06 -06:00
|
|
|
{ 36, 0 }, // Pawn
|
|
|
|
{ 9, 63, 0 }, // Knight OUR PIECES
|
|
|
|
{ 59, 65, 42, 0 }, // Bishop
|
|
|
|
{ 46, 39, 24, -24, 0 }, // Rook
|
2017-12-01 15:02:45 -07:00
|
|
|
{ 97, 100, -42, 137, 268, 0 } // Queen
|
2017-07-08 15:07:25 -06:00
|
|
|
};
|
|
|
|
|
2013-12-02 11:04:09 -07:00
|
|
|
// Endgame evaluation and scaling functions are accessed directly and not through
|
2014-01-05 17:21:44 -07:00
|
|
|
// the function maps because they correspond to more than one material hash key.
|
2014-12-30 02:31:50 -07:00
|
|
|
Endgame<KXK> EvaluateKXK[] = { Endgame<KXK>(WHITE), Endgame<KXK>(BLACK) };
|
2011-04-11 10:12:41 -06:00
|
|
|
|
2011-08-21 13:11:37 -06:00
|
|
|
Endgame<KBPsK> ScaleKBPsK[] = { Endgame<KBPsK>(WHITE), Endgame<KBPsK>(BLACK) };
|
|
|
|
Endgame<KQKRPs> ScaleKQKRPs[] = { Endgame<KQKRPs>(WHITE), Endgame<KQKRPs>(BLACK) };
|
|
|
|
Endgame<KPsK> ScaleKPsK[] = { Endgame<KPsK>(WHITE), Endgame<KPsK>(BLACK) };
|
|
|
|
Endgame<KPKP> ScaleKPKP[] = { Endgame<KPKP>(WHITE), Endgame<KPKP>(BLACK) };
|
2010-04-26 06:43:03 -06:00
|
|
|
|
2015-02-07 02:09:56 -07:00
|
|
|
// Helper used to detect a given material distribution
|
|
|
|
bool is_KXK(const Position& pos, Color us) {
|
|
|
|
return !more_than_one(pos.pieces(~us))
|
|
|
|
&& pos.non_pawn_material(us) >= RookValueMg;
|
2010-04-26 03:42:46 -06:00
|
|
|
}
|
|
|
|
|
Renaming some variables in code
Implements renaming suggestions by Marco Costalba, Günther Demetz,
Gontran Lemaire, Ronald de Man, Stéphane Nicolet, Alain Savard,
Joost VandeVondele, Jerry Donald Watson, Mike Whiteley, xoto10,
and I hope that I haven't forgotten anybody.
Perpetual renaming thread for suggestions:
https://github.com/official-stockfish/Stockfish/issues/1426
No functional change.
2018-03-15 03:44:26 -06:00
|
|
|
bool is_KBPsK(const Position& pos, Color us) {
|
2015-02-07 02:09:56 -07:00
|
|
|
return pos.non_pawn_material(us) == BishopValueMg
|
|
|
|
&& pos.count<BISHOP>(us) == 1
|
|
|
|
&& pos.count<PAWN >(us) >= 1;
|
2010-04-26 03:42:46 -06:00
|
|
|
}
|
|
|
|
|
2015-02-07 02:09:56 -07:00
|
|
|
bool is_KQKRPs(const Position& pos, Color us) {
|
|
|
|
return !pos.count<PAWN>(us)
|
|
|
|
&& pos.non_pawn_material(us) == QueenValueMg
|
|
|
|
&& pos.count<QUEEN>(us) == 1
|
|
|
|
&& pos.count<ROOK>(~us) == 1
|
|
|
|
&& pos.count<PAWN>(~us) >= 1;
|
2010-04-26 03:42:46 -06:00
|
|
|
}
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2013-12-02 11:04:09 -07:00
|
|
|
/// imbalance() calculates the imbalance by comparing the piece count of each
|
2012-12-16 04:00:54 -07:00
|
|
|
/// piece type for both colors.
|
|
|
|
template<Color Us>
|
|
|
|
int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
|
|
|
|
|
|
|
|
const Color Them = (Us == WHITE ? BLACK : WHITE);
|
|
|
|
|
2017-11-18 03:24:23 -07:00
|
|
|
int bonus = 0;
|
2012-12-16 04:00:54 -07:00
|
|
|
|
2017-11-18 03:24:23 -07:00
|
|
|
// Second-degree polynomial material imbalance, by Tord Romstad
|
2014-06-20 15:15:31 -06:00
|
|
|
for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
|
2012-12-16 04:00:54 -07:00
|
|
|
{
|
2014-06-20 15:15:31 -06:00
|
|
|
if (!pieceCount[Us][pt1])
|
2012-12-16 04:00:54 -07:00
|
|
|
continue;
|
|
|
|
|
2016-08-30 12:15:51 -06:00
|
|
|
int v = 0;
|
2012-12-16 04:00:54 -07:00
|
|
|
|
2014-06-20 15:15:31 -06:00
|
|
|
for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
|
2014-12-30 02:31:50 -07:00
|
|
|
v += QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
|
|
|
|
+ QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
|
2012-12-16 04:00:54 -07:00
|
|
|
|
2014-06-20 15:15:31 -06:00
|
|
|
bonus += pieceCount[Us][pt1] * v;
|
2012-12-16 04:00:54 -07:00
|
|
|
}
|
2014-04-03 02:38:11 -06:00
|
|
|
|
2014-06-20 15:15:31 -06:00
|
|
|
return bonus;
|
2012-12-16 04:00:54 -07:00
|
|
|
}
|
|
|
|
|
2011-04-11 10:12:41 -06:00
|
|
|
} // namespace
|
2009-07-17 11:16:20 -06:00
|
|
|
|
2012-12-16 04:00:54 -07:00
|
|
|
namespace Material {
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
/// Material::probe() looks up the current position's material configuration in
|
|
|
|
/// the material hash table. It returns a pointer to the Entry if the position
|
|
|
|
/// is found. Otherwise a new Entry is computed and stored there, so we don't
|
|
|
|
/// have to recompute all when the same material configuration occurs again.
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
Entry* probe(const Position& pos) {
|
2008-10-27 12:07:48 -06:00
|
|
|
|
2011-12-25 03:50:59 -07:00
|
|
|
Key key = pos.material_key();
|
2014-12-30 02:31:50 -07:00
|
|
|
Entry* e = pos.this_thread()->materialTable[key];
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2012-03-31 05:15:57 -06:00
|
|
|
if (e->key == key)
|
|
|
|
return e;
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2013-07-13 09:21:24 -06:00
|
|
|
std::memset(e, 0, sizeof(Entry));
|
2012-03-31 05:15:57 -06:00
|
|
|
e->key = key;
|
|
|
|
e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
|
2017-07-09 03:45:31 -06:00
|
|
|
|
|
|
|
Value npm_w = pos.non_pawn_material(WHITE);
|
|
|
|
Value npm_b = pos.non_pawn_material(BLACK);
|
|
|
|
Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
|
|
|
|
|
|
|
|
// Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
|
|
|
|
e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
|
2009-11-13 05:29:04 -07:00
|
|
|
|
2013-12-02 11:04:09 -07:00
|
|
|
// Let's look if we have a specialized evaluation function for this particular
|
|
|
|
// material configuration. Firstly we look for a fixed configuration one, then
|
|
|
|
// for a generic one if the previous search failed.
|
2015-01-18 02:41:56 -07:00
|
|
|
if ((e->evaluationFunction = pos.this_thread()->endgames.probe<Value>(key)) != nullptr)
|
2012-03-31 05:15:57 -06:00
|
|
|
return e;
|
2008-10-28 12:30:57 -06:00
|
|
|
|
2015-02-07 02:09:56 -07:00
|
|
|
for (Color c = WHITE; c <= BLACK; ++c)
|
|
|
|
if (is_KXK(pos, c))
|
|
|
|
{
|
|
|
|
e->evaluationFunction = &EvaluateKXK[c];
|
|
|
|
return e;
|
|
|
|
}
|
2011-04-11 03:32:55 -06:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
// OK, we didn't find any special evaluation function for the current material
|
|
|
|
// configuration. Is there a suitable specialized scaling function?
|
2011-04-11 10:12:41 -06:00
|
|
|
EndgameBase<ScaleFactor>* sf;
|
2008-11-01 04:38:30 -06:00
|
|
|
|
2015-01-18 02:41:56 -07:00
|
|
|
if ((sf = pos.this_thread()->endgames.probe<ScaleFactor>(key)) != nullptr)
|
2008-10-27 14:54:39 -06:00
|
|
|
{
|
2017-06-04 03:03:23 -06:00
|
|
|
e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned
|
2012-03-31 05:15:57 -06:00
|
|
|
return e;
|
2008-08-31 23:59:13 -06:00
|
|
|
}
|
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
// We didn't find any specialized scaling function, so fall back on generic
|
|
|
|
// ones that refer to more than one material distribution. Note that in this
|
|
|
|
// case we don't return after setting the function.
|
2015-02-07 02:09:56 -07:00
|
|
|
for (Color c = WHITE; c <= BLACK; ++c)
|
|
|
|
{
|
Renaming some variables in code
Implements renaming suggestions by Marco Costalba, Günther Demetz,
Gontran Lemaire, Ronald de Man, Stéphane Nicolet, Alain Savard,
Joost VandeVondele, Jerry Donald Watson, Mike Whiteley, xoto10,
and I hope that I haven't forgotten anybody.
Perpetual renaming thread for suggestions:
https://github.com/official-stockfish/Stockfish/issues/1426
No functional change.
2018-03-15 03:44:26 -06:00
|
|
|
if (is_KBPsK(pos, c))
|
2015-02-07 02:09:56 -07:00
|
|
|
e->scalingFunction[c] = &ScaleKBPsK[c];
|
2008-10-27 14:54:39 -06:00
|
|
|
|
2015-02-07 02:09:56 -07:00
|
|
|
else if (is_KQKRPs(pos, c))
|
|
|
|
e->scalingFunction[c] = &ScaleKQKRPs[c];
|
|
|
|
}
|
2008-10-27 14:54:39 -06:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
|
2008-10-27 14:54:39 -06:00
|
|
|
{
|
2013-06-16 03:59:40 -06:00
|
|
|
if (!pos.count<PAWN>(BLACK))
|
2008-10-27 14:54:39 -06:00
|
|
|
{
|
2013-06-16 03:59:40 -06:00
|
|
|
assert(pos.count<PAWN>(WHITE) >= 2);
|
2014-12-30 02:31:50 -07:00
|
|
|
|
2012-03-31 05:15:57 -06:00
|
|
|
e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
|
2008-10-27 14:54:39 -06:00
|
|
|
}
|
2013-06-16 03:59:40 -06:00
|
|
|
else if (!pos.count<PAWN>(WHITE))
|
2008-10-27 14:54:39 -06:00
|
|
|
{
|
2013-06-16 03:59:40 -06:00
|
|
|
assert(pos.count<PAWN>(BLACK) >= 2);
|
2014-12-30 02:31:50 -07:00
|
|
|
|
2012-03-31 05:15:57 -06:00
|
|
|
e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
|
2008-10-27 14:54:39 -06:00
|
|
|
}
|
2013-06-16 03:59:40 -06:00
|
|
|
else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
|
2008-10-27 14:54:39 -06:00
|
|
|
{
|
2009-08-13 04:45:35 -06:00
|
|
|
// This is a special case because we set scaling functions
|
|
|
|
// for both colors instead of only one.
|
2012-03-31 05:15:57 -06:00
|
|
|
e->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
|
|
|
|
e->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
|
2008-10-27 14:54:39 -06:00
|
|
|
}
|
2008-08-31 23:59:13 -06:00
|
|
|
}
|
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
// Zero or just one pawn makes it difficult to win, even with a small material
|
|
|
|
// advantage. This catches some trivial draws like KK, KBK and KNK and gives a
|
|
|
|
// drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
|
2013-06-16 03:59:40 -06:00
|
|
|
if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
|
2014-12-30 02:31:50 -07:00
|
|
|
e->factor[WHITE] = uint8_t(npm_w < RookValueMg ? SCALE_FACTOR_DRAW :
|
2015-10-05 20:48:47 -06:00
|
|
|
npm_b <= BishopValueMg ? 4 : 14);
|
2011-04-11 06:50:56 -06:00
|
|
|
|
2013-06-16 03:59:40 -06:00
|
|
|
if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
|
2014-12-30 02:31:50 -07:00
|
|
|
e->factor[BLACK] = uint8_t(npm_b < RookValueMg ? SCALE_FACTOR_DRAW :
|
2015-10-05 20:48:47 -06:00
|
|
|
npm_w <= BishopValueMg ? 4 : 14);
|
2011-04-11 03:32:55 -06:00
|
|
|
|
2013-12-31 13:45:20 -07:00
|
|
|
if (pos.count<PAWN>(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
|
|
|
|
e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;
|
|
|
|
|
|
|
|
if (pos.count<PAWN>(BLACK) == 1 && npm_b - npm_w <= BishopValueMg)
|
|
|
|
e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN;
|
|
|
|
|
2013-09-04 22:34:13 -06:00
|
|
|
// Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
|
2013-12-02 11:04:09 -07:00
|
|
|
// for the bishop pair "extended piece", which allows us to be more flexible
|
2011-04-11 03:32:55 -06:00
|
|
|
// in defining bishop pair bonuses.
|
2014-12-30 02:31:50 -07:00
|
|
|
const int PieceCount[COLOR_NB][PIECE_TYPE_NB] = {
|
2013-09-04 22:34:13 -06:00
|
|
|
{ pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
|
|
|
|
pos.count<BISHOP>(WHITE) , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
|
|
|
|
{ pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
|
|
|
|
pos.count<BISHOP>(BLACK) , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
|
2010-11-23 01:09:15 -07:00
|
|
|
|
2014-12-30 02:31:50 -07:00
|
|
|
e->value = int16_t((imbalance<WHITE>(PieceCount) - imbalance<BLACK>(PieceCount)) / 16);
|
2012-03-31 05:15:57 -06:00
|
|
|
return e;
|
2011-04-11 03:32:55 -06:00
|
|
|
}
|
|
|
|
|
2012-12-16 04:00:54 -07:00
|
|
|
} // namespace Material
|