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Subject: Re: KRRKRN - really that drawish? A Crafty game

Author: Sune Fischer

Date: 07:22:13 10/31/02

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On October 31, 2002 at 08:35:37, Peter Berger wrote:

>Crafty seems to evaluate KRRKRN as a dead draw.
>
>KnightDreamer v3.1b - Crafty-19.0
>[D]5R2/8/8/5n1R/4k1rP/8/5K2/8 b - - 0 1
>
>Analysis by Crafty 19.01:
>
>77...Sxh4 78.Txh4 Txh4
>  =  (0.00)   Tiefe: 12/22   00:00:06  4463kN, tb=5298
>77...Sxh4 78.Txh4 Txh4
>  =  (0.00)   Tiefe: 13/23   00:00:16  11939kN, tb=11852
>
>How about this one? Still dead draw according to Crafty - or is it?

Yes, I think so, black to move and can force a tablebase draw:
2	343	5	54		1...Ne3 1.Ke2
2	341	5	124		1...Nd4 1.Ke1
2	0	10	126		1...Nxh4
3	0	15	195		1...Nxh4
4	0	22	497		1...Nxh4
5	0	65	1722		1...Nxh4
6	0	110	5110		1...Nxh4
7	0	217	16686		1...Nxh4
8	0	446	48209		1...Nxh4
9	0	860	151669		1...Nxh4
10	0	1891	448051		1...Nxh4
11	0	3783	1423122		1...Nxh4

>KnightDreamer v3.1b - Crafty-19.0
>8/8/2R5/1R6/4rn2/8/8/k4K2 b - - 0 1
>
>I haven't checked with 6-men statistics or tablebases, but I really doubt that
>this ending is that drawish at all in general - at least a 0.0 can lead to
>serious problems as in this blitzgame:

1...Ra4 looks like a mate in 19:

Entering Nalimov table bases!
Re4e1 : mate in -5 (-299991)
Ka1a2 : mate in -2 (-299997)
Nf4g6 : mate in -2 (-299997)
Nf4e6 : mate in -2 (-299997)
Nf4h5 : mate in -2 (-299997)
Nf4d5 : mate in -2 (-299997)
Nf4h3 : mate in -2 (-299997)
Nf4d3 : mate in -2 (-299997)
Nf4g2 : mate in -2 (-299997)
Nf4e2 : mate in -2 (-299997)
Re4e8 : mate in -1 (-299999)
Re4e7 : mate in -1 (-299999)
Re4e6 : mate in -14 (-299973)
Re4e5 : mate in -1 (-299999)
Re4d4 : mate in -2 (-299997)
Re4c4 : mate in -2 (-299997)
Re4b4 : mate in -2 (-299997)
Re4a4 : mate in -19 (-299963)
Re4e3 : mate in -2 (-299997)
Re4e2 : mate in -11 (-299979)

I'm still testing the implementation, but it seems to play it correctly so I
think it is right :)

-S.



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