Tested using syzygy bench method:
- 2016 random positions ranging between 3 and 10 pieces
- each searched using bench at depth=10
Same node count (and no speed regression).
No functional change.
// like captures and pawn moves but we can easily recover the correct dtz of the
// previous move if we know the position's WDL score.
int dtz_before_zeroing(WDLScore wdl) {
// like captures and pawn moves but we can easily recover the correct dtz of the
// previous move if we know the position's WDL score.
int dtz_before_zeroing(WDLScore wdl) {
- return wdl == WDLWin ? 1 :
- wdl == WDLCursedWin ? 101 :
- wdl == WDLCursedLoss ? -101 :
- wdl == WDLLoss ? -1 : 0;
+ return wdl == WDLWin ? 1 :
+ wdl == WDLCursedWin ? 101 :
+ wdl == WDLBlessedLoss ? -101 :
+ wdl == WDLLoss ? -1 : 0;
}
// Return the sign of a number (-1, 0, 1)
}
// Return the sign of a number (-1, 0, 1)
struct DTZEntryPiece {
PairsData* precomp;
struct DTZEntryPiece {
PairsData* precomp;
- uint16_t map_idx[4]; // WDLWin, WDLLoss, WDLCursedWin, WDLCursedLoss
+ uint16_t map_idx[4]; // WDLWin, WDLLoss, WDLCursedWin, WDLBlessedLoss
if ( (wdl == WDLWin && !(flags & TBFlag::WinPlies))
|| (wdl == WDLLoss && !(flags & TBFlag::LossPlies))
|| wdl == WDLCursedWin
if ( (wdl == WDLWin && !(flags & TBFlag::WinPlies))
|| (wdl == WDLLoss && !(flags & TBFlag::LossPlies))
|| wdl == WDLCursedWin
- || wdl == WDLCursedLoss)
+ || wdl == WDLBlessedLoss)
value *= 2;
return value + 1;
value *= 2;
return value + 1;
return 0;
if (*result != CHANGE_STM)
return 0;
if (*result != CHANGE_STM)
- return (dtz + 100 * (wdl == WDLCursedLoss || wdl == WDLCursedWin)) * sign_of(wdl);
+ return (dtz + 100 * (wdl == WDLBlessedLoss || wdl == WDLCursedWin)) * sign_of(wdl);
// DTZ stores results for the other side, so we need to do a 1-ply search and
// find the winning move that minimizes DTZ.
// DTZ stores results for the other side, so we need to do a 1-ply search and
// find the winning move that minimizes DTZ.
// Use 50-move counter to determine whether the root position is
// won, lost or drawn.
// Use 50-move counter to determine whether the root position is
// won, lost or drawn.
+ WDLScore wdl = WDLDraw;
- wdl = (dtz + cnt50 <= 100) ? 2 : 1;
+ wdl = (dtz + cnt50 <= 100) ? WDLWin : WDLCursedWin;
- wdl = (-dtz + cnt50 <= 100) ? -2 : -1;
+ wdl = (-dtz + cnt50 <= 100) ? WDLLoss : WDLBlessedLoss;
// Determine the score to report to the user.
score = WDL_to_value[wdl + 2];
// Determine the score to report to the user.
score = WDL_to_value[wdl + 2];
// If the position is winning or losing, but too few moves left, adjust the
// score to show how close it is to winning or losing.
// NOTE: int(PawnValueEg) is used as scaling factor in score_to_uci().
// If the position is winning or losing, but too few moves left, adjust the
// score to show how close it is to winning or losing.
// NOTE: int(PawnValueEg) is used as scaling factor in score_to_uci().
- if (wdl == 1 && dtz <= 100)
+ if (wdl == WDLCursedWin && dtz <= 100)
score = (Value)(((200 - dtz - cnt50) * int(PawnValueEg)) / 200);
score = (Value)(((200 - dtz - cnt50) * int(PawnValueEg)) / 200);
- else if (wdl == -1 && dtz >= -100)
+ else if (wdl == WDLBlessedLoss && dtz >= -100)
score = -(Value)(((200 + dtz - cnt50) * int(PawnValueEg)) / 200);
// Now be a bit smart about filtering out moves.
score = -(Value)(((200 + dtz - cnt50) * int(PawnValueEg)) / 200);
// Now be a bit smart about filtering out moves.
namespace Tablebases {
enum WDLScore {
namespace Tablebases {
enum WDLScore {
- WDLLoss = -2, // Loss
- WDLCursedLoss = -1, // Loss, but draw under 50-move rule
- WDLDraw = 0, // Draw
- WDLCursedWin = 1, // Win, but draw under 50-move rule
- WDLWin = 2, // Win
+ WDLLoss = -2, // Loss
+ WDLBlessedLoss = -1, // Loss, but draw under 50-move rule
+ WDLDraw = 0, // Draw
+ WDLCursedWin = 1, // Win, but draw under 50-move rule
+ WDLWin = 2, // Win
inline std::ostream& operator<<(std::ostream& os, const WDLScore v) {
inline std::ostream& operator<<(std::ostream& os, const WDLScore v) {
- os << (v == WDLLoss ? "Loss" :
- v == WDLCursedLoss ? "Cursed loss" :
- v == WDLDraw ? "Draw" :
- v == WDLCursedWin ? "Cursed win" :
- v == WDLWin ? "Win" : "None");
+ os << (v == WDLLoss ? "Loss" :
+ v == WDLBlessedLoss ? "Blessed loss" :
+ v == WDLDraw ? "Draw" :
+ v == WDLCursedWin ? "Cursed win" :
+ v == WDLWin ? "Win" : "None");