kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-30 08:43:09 +00:00
Code Issues Releases Wiki Activity

Merge Connected and Candidate

Browse source 
These two notions are very correlated. Since connected has the most
generality, it makes sense to generalize it to encompass what is
covered by candidate.

STC:
LLR: 4.03 (-2.94,2.94) [-3.00,1.00]
Total: 11970 W: 2577 L: 2379 D: 7014

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 13194 W: 2389 L: 2255 D: 8550

bench 7328585
This commit is contained in:
lucasart 2014-10-06 19:26:30 +08:00 • committed by Joona Kiiski
parent 15e2191111
commit 069073ea68
4 changed files with 17 additions and 53 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
src/evaluate.cpp
View file

@ -626,13 +626,13 @@ namespace {
}
// evaluate_unstoppable_pawns() scores the most advanced among the passed and
// candidate pawns. In case both players have no pieces but pawns, this is
// somewhat related to the possibility that pawns are unstoppable.
// evaluate_unstoppable_pawns() scores the most advanced passed pawn. In case
// both players have no pieces but pawns, this is somewhat related to the
// possibility that pawns are unstoppable.
Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) {
Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
Bitboard b = ei.pi->passed_pawns(us);
return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO;
}

1
src/main.cpp
View file

@ -36,7 +36,6 @@ int main(int argc, char* argv[]) {
Position::init();
Bitbases::init_kpk();
Search::init();
Pawns::init();
Eval::init();
Threads.init();
TT.resize(Options["Hash"]);

58
src/pawns.cpp
View file

@ -49,13 +49,8 @@ namespace {
{ S(20, 28), S(29, 31), S(33, 31), S(33, 31),
S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
// Connected pawn bonus by file and rank (initialized by formula)
Score Connected[FILE_NB][RANK_NB];
// Candidate passed pawn bonus by rank
const Score CandidatePassed[RANK_NB] = {
S( 0, 0), S( 6, 13), S(6,13), S(14,29),
S(34,68), S(83,166), S(0, 0), S( 0, 0) };
// Connected bonus by rank
const int Connected[RANK_NB] = {0, 6, 15, 10, 57, 75, 135, 258};
// Levers bonus by rank
const Score Lever[RANK_NB] = {
@ -96,8 +91,7 @@ namespace {
Bitboard b, p, doubled;
Square s;
File f;
bool passed, isolated, opposed, connected, backward, candidate, unsupported, lever;
bool passed, isolated, opposed, connected, backward, unsupported, lever;
Score value = SCORE_ZERO;
const Square* pl = pos.list<PAWN>(Us);
const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
@ -105,7 +99,7 @@ namespace {
Bitboard ourPawns = pos.pieces(Us , PAWN);
Bitboard theirPawns = pos.pieces(Them, PAWN);
e->passedPawns[Us] = e->candidatePawns[Us] = 0;
e->passedPawns[Us] = 0;
e->kingSquares[Us] = SQ_NONE;
e->semiopenFiles[Us] = 0xFF;
e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
@ -117,7 +111,8 @@ namespace {
{
assert(pos.piece_on(s) == make_piece(Us, PAWN));
f = file_of(s);
Rank r = rank_of(s), rr = relative_rank(Us, s);
File f = file_of(s);
// This file cannot be semi-open
e->semiopenFiles[Us] &= ~(1 << f);
@ -162,14 +157,6 @@ namespace {
assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns));
// A not-passed pawn is a candidate to become passed, if it is free to
// advance and if the number of friendly pawns beside or behind this
// pawn on adjacent files is higher than or equal to the number of
// enemy pawns in the forward direction on the adjacent files.
candidate = !(opposed | passed | backward | isolated)
&& (b = pawn_attack_span(Them, s + pawn_push(Us)) & ourPawns) != 0
&& popcount<Max15>(b) >= popcount<Max15>(pawn_attack_span(Us, s) & theirPawns);
// Passed pawns will be properly scored in evaluation because we need
// full attack info to evaluate passed pawns. Only the frontmost passed
// pawn on each file is considered a true passed pawn.
@ -189,19 +176,15 @@ namespace {
if (backward)
value -= Backward[opposed][f];
if (connected)
value += Connected[f][relative_rank(Us, s)];
if (connected) {
int bonus = Connected[rr];
if (ourPawns & adjacent_files_bb(f) & rank_bb(r))
bonus += (Connected[rr+1] - Connected[rr]) / 2;
value += make_score(bonus / 2, bonus >> opposed);
}
if (lever)
value += Lever[relative_rank(Us, s)];
if (candidate)
{
value += CandidatePassed[relative_rank(Us, s)];
if (!doubled)
e->candidatePawns[Us] |= s;
}
value += Lever[rr];
}
b = e->semiopenFiles[Us] ^ 0xFF;
@ -218,21 +201,6 @@ namespace {
namespace Pawns {
/// init() initializes some tables by formula instead of hard-coding their values
void init() {
const int bonusByFile[] = { 1, 3, 3, 4, 4, 3, 3, 1 };
for (Rank r = RANK_1; r < RANK_8; ++r)
for (File f = FILE_A; f <= FILE_H; ++f)
{
int bonus = r * (r - 1) * (r - 2) + bonusByFile[f] * (r / 2 + 1);
Connected[f][r] = make_score(bonus, bonus);
}
}
/// probe() takes a position as input, computes a Entry object, and returns a
/// pointer to it. The result is also stored in a hash table, so we don't have
/// to recompute everything when the same pawn structure occurs again.

3
src/pawns.h
View file

@ -35,7 +35,6 @@ 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 semiopen_file(Color c, File f) const {
return semiopenFiles[c] & (1 << f);
@ -68,7 +67,6 @@ struct Entry {
Key key;
Score value;
Bitboard passedPawns[COLOR_NB];
Bitboard candidatePawns[COLOR_NB];
Bitboard pawnAttacks[COLOR_NB];
Square kingSquares[COLOR_NB];
Score kingSafety[COLOR_NB];
@ -81,7 +79,6 @@ struct Entry {
typedef HashTable<Entry, 16384> Table;
void init();
Entry* probe(const Position& pos, Table& entries);
} // namespace Pawns