opelly/Stockfish
1
0
Fork 0
mirror of https://github.com/opelly27/Stockfish.git synced 2026-05-20 10:57:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

Move draw by material check

Browse Source 
It is more natural to test this case among
others material distributions.

No functional change.
This commit is contained in:
Marco Costalba
2013-09-08 05:49:04 -07:00
parent 0515ad0fb0
commit 490f67a3f8
3 changed files with 17 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/material.cpp
+11 -4
View File
@@ -173,10 +173,18 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
return e;
}
// Draw by insufficient material (trivial draws like KK, KBK and KNK)
if ( !pos.pieces(PAWN)
&& pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) <= BishopValueMg)
{
e->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
return e;
}
// Minor piece endgame with at least one minor piece per side and
// no pawns. Note that the case KmmK is already handled by KXK.
if (!pos.pieces(PAWN) && !pos.pieces(ROOK) && !pos.pieces(QUEEN))
{
// Minor piece endgame with at least one minor piece per side and
// no pawns. Note that the case KmmK is already handled by KXK.
assert((pos.pieces(WHITE, KNIGHT) | pos.pieces(WHITE, BISHOP)));
assert((pos.pieces(BLACK, KNIGHT) | pos.pieces(BLACK, BISHOP)));
@@ -240,8 +248,7 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
}
}
// No pawns makes it difficult to win, even with a material advantage. This
// catches some trivial draws like KK, KBK and KNK
// No pawns makes it difficult to win, even with a material advantage
if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
{
e->factor[WHITE] = (uint8_t)