mirror of
https://github.com/peterosterlund2/droidfish.git
synced 2024-12-04 01:11:01 +01:00
55 lines
1.8 KiB
C++
55 lines
1.8 KiB
C++
#ifndef RTB_PROBE_HPP_
|
|
#define RTB_PROBE_HPP_
|
|
|
|
#include <string>
|
|
|
|
class Position;
|
|
|
|
namespace Syzygy {
|
|
|
|
extern int TBLargest;
|
|
|
|
void init(const std::string& path);
|
|
|
|
// Probe the WDL table for a particular position.
|
|
// If *success != 0, the probe was successful.
|
|
// The return value is from the point of view of the side to move:
|
|
// -2 : loss
|
|
// -1 : loss, but draw under 50-move rule
|
|
// 0 : draw
|
|
// 1 : win, but draw under 50-move rule
|
|
// 2 : win
|
|
int probe_wdl(Position& pos, int *success);
|
|
|
|
// Probe the DTZ table for a particular position.
|
|
// If *success != 0, the probe was successful.
|
|
// The return value is from the point of view of the side to move:
|
|
// n < -100 : loss, but draw under 50-move rule
|
|
// -100 <= n < -1 : loss in n ply (assuming 50-move counter == 0)
|
|
// 0 : draw
|
|
// 1 < n <= 100 : win in n ply (assuming 50-move counter == 0)
|
|
// 100 < n : win, but draw under 50-move rule
|
|
//
|
|
// The return value n can be off by 1: a return value -n can mean a loss
|
|
// in n+1 ply and a return value +n can mean a win in n+1 ply. This
|
|
// cannot happen for tables with positions exactly on the "edge" of
|
|
// the 50-move rule.
|
|
//
|
|
// This implies that if dtz > 0 is returned, the position is certainly
|
|
// a win if dtz + 50-move-counter <= 99. Care must be taken that the engine
|
|
// picks moves that preserve dtz + 50-move-counter <= 99.
|
|
//
|
|
// If n = 100 immediately after a capture or pawn move, then the position
|
|
// is also certainly a win, and during the whole phase until the next
|
|
// capture or pawn move, the inequality to be preserved is
|
|
// dtz + 50-movecounter <= 100.
|
|
//
|
|
// In short, if a move is available resulting in dtz + 50-move-counter <= 99,
|
|
// then do not accept moves leading to dtz + 50-move-counter == 100.
|
|
//
|
|
int probe_dtz(Position& pos, int *success);
|
|
|
|
}
|
|
|
|
#endif
|