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Subject: Re: What shortest mate that you can find for this position?

Author: Tim Foden

Date: 03:44:52 01/18/01

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On January 17, 2001 at 17:11:45, leonid wrote:

>Hi!
>
>Position below contain mate. If you can find shortest mate that 11 moves (my
>selective search can't find here below 11 and frute force search is too time
>expensive), please say what you found.
>
>[D]3k4/2bqb3/2qnq3/2nrn3/1Qqnq3/NBNq4/PPP2pR1/KB4R1 b
>
>Leonid.

GLC takes quite a while to find this mate in 9:

  7   1:03  60.80  11383k  Qxb4 Rg8+ Ne8 Ncb5 Ncxb3+ axb3 Nxc2+ Nxc2 fxg1=Q
                           Rxg1 Qbxb5
  8   1:06     ++  11764k  Qxb4    (a=60.30 b=61.30 e=61.30)
  8  48:47 320.81 548788k  Qxb4 Rg8+ Ne8 Rxe8+ Qxe8 Rc1 Ncxb3+ cxb3 Nxb3+ axb3
                           Qxa3+ bxa3 Qcxc3+ Ka2 Qxb3+ Ka1 Qed4+ Rc3 Qd4xc3#

(I /really/ shall have to look into the search explosion problem!)

After (lots of) fiddling around with the search extension values, GLC finds
this mate in 8:

  8   1:31  61.49  16384k  Qxb4 Ncb5 Ncxb3+ axb3 fxg1=R Rxg1 Qdxb5 Rg8+ Qxg8
                           Nxb5 N6xb5
  9   1:37     ++  17239k  Qxb4    (a=60.99 b=61.99 e=61.99)
  9   2:31 320.83  27570k  Qxb4 Ncb5 Ncxb3+ axb3 Nxc2+ Nxc2 Qcxc2 Rg8+ Ne8
                           Bxc2 f1=Q+ Rxf1 Qxf1+ Bd1 Rxd1+ Ka2 Qexb3#
  9   4:33 320.83  51782k  Qxb4 Ncb5 Ncxb3+ axb3 Nxc2+ Nxc2 Qcxc2 Rg8+ Ne8
                           Bxc2 f1=Q+ Rxf1 Qxf1+ Bd1 Rxd1+ Ka2 Qexb3#

Cheers, Tim.



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