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

Move Tempo to evaluation

Browse source 
Apart from the semplification it is now more clear that
the actual Tempo added was half of the indicated score.
This is becuase at start compute_psq_score() added half
Tempo unit and in do_move() white/black were respectively
adding/subtracting one Tempo unit.

Now we have directly halved Tempo constant and everything
is more clear.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2012-04-09 10:34:17 +01:00
parent 68885f78f3
commit e72b93e44f
2 changed files with 16 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
src/evaluate.cpp
View file

@ -150,6 +150,9 @@ namespace {
#undef S
// Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(24, 11);
// Rooks and queens on the 7th rank (modified by Joona Kiiski)
const Score RookOn7thBonus = make_score(47, 98);
const Score QueenOn7thBonus = make_score(27, 54);
@ -362,14 +365,15 @@ Value do_evaluate(const Position& pos, Value& margin) {
Value margins[2];
Score score, mobilityWhite, mobilityBlack;
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables).
score = pos.psq_score();
// margins[] store the uncertainty estimation of position's evaluation
// that typically is used by the search for pruning decisions.
margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables) and adding
// Tempo bonus. Score is computed from the point of view of white.
score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
// Probe the material hash table
ei.mi = pos.this_thread()->materialTable.probe(pos);
score += ei.mi->material_value();

31
src/position.cpp
View file

@ -62,15 +62,8 @@ const Value PieceValueEndgame[17] = {
RookValueEndgame, QueenValueEndgame
};
namespace {
// Bonus for having the side to move (modified by Joona Kiiski)
const Score Tempo = make_score(48, 22);
// To convert a Piece to and from a FEN char
const string PieceToChar(" PNBRQK pnbrqk .");
}
// To convert a Piece to and from a FEN char
static const string PieceToChar(" PNBRQK pnbrqk .");
/// CheckInfo c'tor
@ -934,9 +927,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
}
}
// Finish
sideToMove = ~sideToMove;
st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
assert(pos_is_ok());
}
@ -1127,9 +1118,7 @@ void Position::do_castle_move(Move m) {
// Update checkers BB
st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
// Finish
sideToMove = ~sideToMove;
st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
else
// Undo: point our state pointer back to the previous state
@ -1172,7 +1161,6 @@ void Position::do_null_move(StateInfo& backupSt) {
st->epSquare = SQ_NONE;
st->rule50++;
st->pliesFromNull = 0;
st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
assert(pos_is_ok());
@ -1406,18 +1394,15 @@ Key Position::compute_material_key() const {
/// updated by do_move and undo_move when the program is running in debug mode.
Score Position::compute_psq_score() const {
Bitboard b;
Score result = SCORE_ZERO;
Bitboard b = pieces();
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
{
b = pieces(pt, c);
while (b)
result += pieceSquareTable[make_piece(c, pt)][pop_1st_bit(&b)];
}
while (b)
{
Square s = pop_1st_bit(&b);
result += pieceSquareTable[piece_on(s)][s];
}
result += (sideToMove == WHITE ? Tempo / 2 : -Tempo / 2);
return result;
}