I too notice the error in the FEN position - the fifty counter should be 0. There is some bugs in xboard with editing positions when remnant information from previous games/positions corrupts the fifty counter on saving. I discovered it as I have to look into the fifty counter as the bug in my search was a corrupt fifty counter.sje wrote:How can the half move counter be five when the full move number is one? The FEN input scanner should really check for this.Chan Rasjid wrote:This is a difficult KPK position which requires coding for the piece races:
[D]4k3/8/8/8/K7/8/4P3/8 w - - 5 1[/D]
Anyways,
[d]4k3/8/8/8/K7/8/4P3/8 w - - 0 1[/d]
Symbolic says:Code: Select all
[] dtbm Ka3 Even Ka5 Even Kb3 MateIn23 Kb4 MateIn23 Kb5 MateIn23 e3 Even e4 Even [] dg 1 Kb3 Kd7 2 Kc3 Kc6 3 Kc4 Kd6 4 Kd4 Ke6 5 Ke4 Kd6 6 Kf5 Ke7 7 Ke5 Kd7 8 Kf6 Kc6 9 Ke6 Kb5 10 Kd6 Ka6 11 Kd7 Ka5 12 e4 Ka4 13 Kd6 Ka3 14 e5 Ka2 15 Kc5 Ka1 16 Kc4 Ka2 17 e6 Kb2 18 e7 Kc2 19 e8=Q Kd2 20 Qe4 Kc1 21 Kc3 Kd1 22 Qe5 Kc1 23 Qe1# 1-0
Now my KPK rountine is working perfectly. It is just probe KPK bitbase and then returning a value. The return for a probe win is the 'optimally correct' value as pointed out by Ronald - just 8xPawns - distance_to_promote.
My analysis output is (the only correct PV before queening?) :
Best Regards,info depth 41, score +7871 cp, time 7381 ms, nodes 22541387 nps 3053974, pv
a4b3 e8f7 b3c4 f7e6 c4d4 e6d6 e2e3 d6e6 d4e4 e6f6 e4d5 f6e7 d5e5 e7f7 e5d6 f7e8 e3e4 e8d8 e4e5 d8e8 d6e6 e8d8 e6f7 d8d7 e5e6 d7d6 e6e7 d6e5 e7e8q e5d4 e8d8 d4c3
Rasjid.