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Subject: Re: Open Letter by Hsu: Kasparov does not want a rematch

Author: Jeremiah Penery

Date: 14:45:21 01/10/00

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On January 10, 2000 at 16:30:58, Robert Hyatt wrote:

>No program _ever_ found the draw.  It is over 60 plies deep from the ending
>position...  which is hopeless unless you start to give a program 24 hours or
>more to search.

Just since this has come up...
I let my modified Crafty run on this for about a month over Xmas break...This is
what it came up with:

I gave it the position before the final move of the game, and told it to search
that move.

White(45): search Ra6
              time surplus   0.00  time limit 30.00 (3:00)
         nss  depth   time  score   variation (1)
                1->   0.01  -0.58   45. Ra6 Qxc6 46. dxc6
                2->   0.04  -0.58   45. Ra6 Qxc6 46. dxc6
                3->   0.06  -0.87   45. Ra6 Qxc6 46. dxc6 Bc7
                4     0.07     ++   45. Ra6!!
                4->   0.09   0.33   45. Ra6 Qxc6 46. dxc6 Bc7 47. Ke2
                5     0.10     --   45. Ra6
                5->   0.14  -0.07   45. Ra6 Qxc6 46. dxc6 Bc7 47. Ke2 Ke7
                6     0.17     ++   45. Ra6!!
                6->   0.19   0.32   45. Ra6 Qxc6 46. dxc6 Bc7 47. Ke2 Ke7
                7     0.28     ++   45. Ra6!!
                7->   0.41   0.89   45. Ra6 Qxc6 46. dxc6 h5 47. Ra7+ Be7
                                    48. Ke2 Rd8 49. Ke3
                8     0.61     ++   45. Ra6!!
                8->   0.90   1.28   45. Ra6 Qxc6 46. dxc6 h5 47. Ra7+ Be7
                                    48. Ke2 Rd8 49. Ke3
                9->   1.40   1.22   45. Ra6 Qxc6 46. dxc6 Ke8 47. Ra7 Rd8
                                    48. Rb7 Ra8 49. Rxb5 Bc7
               10     3.44     ++   45. Ra6!!
               10->   3.76   1.62   45. Ra6 Qxc6 46. dxc6 Ke8 47. Ra7 Rc8
                                    48. Ke2 Rc7 49. Ra5 Ke7 50. Rxb5
               11->   5.78   1.61   45. Ra6 Qxc6 46. dxc6 Kf8 47. Ra7 Rc8
                                    48. Ke2 h5 49. Rb7 Rc7 50. Rxb5 Ke7
               12->  20.51   1.72   45. Ra6 Qxc6 46. dxc6 Kf8 47. Ra7 Rc8
                                    48. Ke2 Bc7 49. Rb7 Ke7 50. Rxb5 Kd6
                                    51. Ke3
               13->   2:10   1.68   45. Ra6 Qe3 46. Qd7+ Kg8 47. Qxd6 Rf8
                                    48. Qe6+ Kh8 49. Qe7 Rg8 50. Bf3 Qc1+
                                    51. Kf2 Qd2+ 52. Be2 Qf4+ 53. Ke1 Qc1+
                                    54. Kf2 Qxc3
               14     3:26     --   45. Ra6
               14->   7:46   0.51   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. Kh3 Qxf5+
                                    54. Kh2 Qh7
               15->  12:51   0.44   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. g3 Qf2+
                                    54. Kh3 Qxe2 55. Qd7+ Kf8 56. Qxb5
               16->  24:33   0.65   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. Kh3 Qxf5+
                                    54. Kh2 Qf4+ 55. Kg1 Qc1+ 56. Kf2 Qh6
               17->  62:44   0.65   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. Kh3 Qxf5+
                                    54. Kh2 Qf4+ 55. Kg1 Qe3+ 56. Kf1 Qf4+
                                    57. Ke1 <HT>
               18-> 257:24   0.73   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. Kh3 Qxf5+
                                    54. Kh2 Qf4+ 55. Kg1 Qe3+ 56. Kf1 Qc1+
                                    57. Kf2 Qf4+ 58. Bf3 Qh6
               19-> 784:39   0.75   45. Ra6 Qe3 46. Qxd6 Re8 47. h4 h5
                                    48. Bf3 Qc1+ 49. Kf2 Qd2+ 50. Be2 Qf4+
                                    51. Kg1 Qe3+ 52. Kh2 Qf4+ 53. Kh3 Qxf5+
                                    54. Kh2 Qf4+ 55. Kg1 Qe3+ 56. Kf1 Qc1+
                                    57. Kf2 Qf4+ 58. Bf3 Qd2+ 59. Kf1 Qh6
               20   5177:33     --   45. Ra6

I was optimistic here...Up until now, it had been following the PV given on the
Rebel site as the longest drawing PV (36 ply - given below), and I hoped that it
might have discovered the quiet move (60. ...Qc1) in that line which would allow
the draw...It was not so, and it changed the entire PV.  I did not know this
until 3 weeks later, however, because I left for break before the resolution of
the fail-low.

--
This is from Ed's page:
45.Ra6? Qe3! 46.Qxd6 Re8! 47.h4! h5! 48.Bf3 Qc1+ 49.Kf2 Qd2+ 50.Be2 Qf4+ 51.Kg1
Qe3+ 52.Kh2 Qf4+ 53.Kh3 Qxf5+ 54.Kh2 Qf4+ 55.Kg1 Qe3+ 56.Kf1 Qc1+ 57.Kf2 Qf4+
58.Ke1 Qc1+ 59.Bd1 Qxc3+ 60.Kf1 Qc1! 61.Ke2 Qb2+ 62.Kf1 Qc1
--
               20-> 8855:29   0.00   45. Ra6 Qe3 46. Qxd6 Re8 47. Qe6+ Rxe6
                                    48. fxe6+ Ke7 49. Bg6 Qc1+ 50. Kf2
                                    Qb2+ 51. Kg3 Qxc3+ 52. Kh2 Qe3 53.
                                    Bf5 Qf4+ 54. Kh1 Qxf5 55. Ra7+ Kd8
                                    56. Ra8+ Kc7 57. e7 Qf1+ 58. Kh2 Qf4+
                                    59. Kh1 Qc1+ 60. Kh2 Qf4+
               21-> 20053:38   0.15   45. Ra6 Qe3 46. Qxd6 Re8 47. Qd7+ Re7
                                    48. Qc6 Qxe4 49. d6 Qd3+ 50. Kg1 Re8
                                    51. Ra7+ Kf8 52. Qc5 Rd8 53. Rxg7 Qd1+
                                    54. Kh2 Qxd6 55. Rh7 Qxc5 56. bxc5
                                    Rd3 57. Rxh6 Ke7

I'm only left wondering why it left the PV it had before...

               22   23388:31     ++   45. Ra6!!

Now I was disappointed that the score is going back up.

It ended up searching about 40000 minutes before I stopped it - the fail-high
had not resolved.  Total nodes ~= 315 billion.



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