Kind of semantics, though.tpoppins wrote:"+128.xx" indicates a tablebase win, it's not a mate score; I believe we've gone over this already.MikeB wrote:latest McB now under 130 seconds with mate score
<snip>
Code: Select all
dep score nodes time (not shown: tbhits knps seldep) 70 +128.34 5.70G 2:34.15 b6 Be8 b7 Bb5 b8=R Ba6 Rb6 Bf1 Rb1 Kg2 Ke4 Be2 Kf4 Bd3 Rb6 Be2 Rc6 Bb5 Rc7 Be2 Kxg4 Kxf2 Kh3 Bf1+ Kh4 Kg2 g4 Bd3 Bg3 Be4 Rd7 Bc6 Rd2+ Kg1 Bh2+ Kf1 Kg3 Ke1 Rf2 Bb7 Rxf3
The tablebase lookup has proven there is a checkmate.
In some sense, that is a mate score.
Yes, technically, a mate score is:
"A value greater than 32000 indicates the availability of a forced mate to the
active player. The number of plies until mate is given by subtracting the
evaluation from the value 32767. Thus, a winning mate in N fullmoves is a mate
in ((2 * N) - 1) halfmoves (or ply) and has a corresponding centipawn
evaluation of (32767 - ((2 * N) - 1)). For example, a mate on the move (mate
in one) has a centipawn evaluation of 32766 while a mate in five has a
centipawn evaluation of 32758.
A value less than -32000 indicates the availability of a forced mate to the
passive player. The number of plies until mate is given by subtracting the
evaluation from the value -32767 and then negating the result. Thus, a losing
mate in N fullmoves is a mate in (2 * N) halfmoves (or ply) and has a
corresponding centipawn evaluation of (-32767 + (2 * N)). For example, a mate
after the move (losing mate in one) has a centipawn evaluation of -32765 while
a losing mate in five has a centipawn evaluation of -32757."
But a tablebase hit is the same thing without a definite distance in plies.
IOW:
A value greater than <tb-indicator-value> indicates the availability of a forced mate to the active player.
where <tb-indicator-value> varies from tb to tb and engine to engine.
Which is confusing, to say the least.
Komodo says values around 250.
SF says values around 128.
Both reading from Syzygy files.
The worst part of this sort of scoring is that it is larger than mate values in magnitude (32.766 pawns is the biggest score in the PGN standard).
Which is also ironic because of this:
f:\utils\imbalance.exe < q:\absurd.epd
>> ** IMBALANCED ** << [14415]
4k3/8/Q7/8/1QQ5/N3N3/3QQQQQ/R1BQKB1R w KQ - )[d]4k3/8/Q7/8/1QQ5/N3N3/3QQQQQ/R1BQKB1R w KQ -
