/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2016 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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
// Isolated pawn penalty by opposed flag and file
const Score Isolated[2][FILE_NB] = {
- { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
- S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
- { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
- S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
+ { S(31, 36), S(45, 41), S(50, 41), S(50, 41),
+ S(50, 41), S(50, 41), S(45, 41), S(31, 36) },
+ { S(21, 24), S(30, 28), S(33, 28), S(33, 28),
+ S(33, 28), S(33, 28), S(30, 28), S(21, 24) } };
// Backward pawn penalty by opposed flag
- const Score Backward[2] = { S(67, 42), S(49, 24) };
-
- // Unsupported pawn penalty, for pawns which are neither isolated or backward
- const Score Unsupported = S(20, 10);
+ const Score Backward[2] = { S(56, 33), S(41, 19) };
+
+ // Unsupported pawn penalty for pawns which are neither isolated or backward,
+ // by number of pawns it supports [less than 2 / exactly 2].
+ const Score Unsupported[2] = { S(17, 8), S(21, 12) };
// Connected pawn bonus by opposed, phalanx, twice supported and rank
Score Connected[2][2][2][RANK_NB];
-
+
// Doubled pawn penalty by file
const Score Doubled[FILE_NB] = {
- S(13, 43), S(20, 48), S(23, 48), S(23, 48),
- S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
+ S(11, 34), S(17, 38), S(19, 38), S(19, 38),
+ S(19, 38), S(19, 38), S(17, 38), S(11, 34) };
// Lever bonus by rank
const Score Lever[RANK_NB] = {
S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
- S(20, 20), S(40, 40), S(0, 0), S(0, 0) };
-
- // Center bind bonus, when two pawns controls the same central square
- const Score CenterBind = S(16, 0);
+ S(17, 16), S(33, 32), S(0, 0), S(0, 0) };
// Weakness of our pawn shelter in front of the king by [distance from edge][rank]
const Value ShelterWeakness[][RANK_NB] = {
const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
- const Bitboard CenterBindMask =
- Us == WHITE ? (FileDBB | FileEBB) & (Rank5BB | Rank6BB | Rank7BB)
- : (FileDBB | FileEBB) & (Rank4BB | Rank3BB | Rank2BB);
-
Bitboard b, neighbours, doubled, supported, phalanx;
Square s;
bool passed, isolated, opposed, backward, lever, connected;
score -= Backward[opposed];
else if (!supported)
- score -= Unsupported;
+ score -= Unsupported[more_than_one(neighbours & rank_bb(s + Up))];
if (connected)
score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
b = e->semiopenFiles[Us] ^ 0xFF;
e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
- b = shift_bb<Right>(ourPawns) & shift_bb<Left>(ourPawns) & CenterBindMask;
- score += CenterBind * popcount<Max15>(b);
-
return score;
}
void init()
{
- static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 };
+ static const int Seed[RANK_NB] = { 0, 8, 19, 13, 71, 94, 169, 324 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
{
int v = (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
v += (apex ? v / 2 : 0);
- Connected[opposed][phalanx][apex][r] = make_score(3 * v / 2, v);
+ Connected[opposed][phalanx][apex][r] = make_score(v, v * 5 / 8);
}
}
if (pawns)
while (!(DistanceRingBB[ksq][minKingPawnDistance++] & pawns)) {}
- if (relative_rank(Us, ksq) > RANK_4)
- return make_score(0, -16 * minKingPawnDistance);
-
Value bonus = shelter_storm<Us>(pos, ksq);
// If we can castle use the bonus after the castling if it is bigger