From: jhc@m2lll.uucp (James H. Coombs)
Subject: Re: Piket-van Mil
Reply-To: jhc@iris.brown.edu.UUCP (James H. Coombs)
Organization: IRIS - Brown University
Date: Wed, 19 Aug 1992 23:17:07 GMT

In article <1992Aug17.225310.10561@cbnewsh.cb.att.com> gls@windmill.att.com (The Human Windmill) writes:
>In <28536@option.GBA.NYU.EDU>, mginsbur@option.GBA.NYU.EDU writes:

>> Hello, would someone with a reasonable computer like to try this position:

It would help to know what processing power you are looking for.  After
trying out the position, it occurs to me now that I am providing
analysis from a program that is playing at about 2300, while your
rating is about 2500.  But then what program+computer offers 2700?  And
why would we expect a computer to tell us the soundness of an opening
move that an SM can't refute readily?  From my reading of *Petrosian's
Legacy*, I would think that opening refutations frequently require
extrarodinary clarity and depth of thought based upon strategic as well
as tactical prowess.  Computers do not currently give us the necessary
strategic prowess.

These are genuine questions from a class D player, who now blunders on
with his computer's analysis.

>> 1. Nf3 f5
>> 2. e4  fe
>> 3. Ng5 d5
>> 4. d3  Qd6
>> 5. Nc3 h6
>> 6. Nb5  Qc6
>> ... The game Piket-van Mil, Dutch Ch. 1992, saw but shed absolutely no light
>> on the correctness of 7. de hg 8. ed.

>on Gnuchess 4.0 on a FAST mainframe....
>The program apparently didn't think much of 8. ed -- it played for the end-
>game with 8. Q:d5.  After 8... Na6; 9. Q:c6+ bc; 10. Nd4 Nb4 it was obvious
>that White lacked compensation.

I tried Zarkov 2.6 on a 486/25 at 40/2.  Zarkov made the same choice of
Qxd5 over exd5, although the analysis of 7...hxg5 suggests 8.exd5,
which is rejected on move 8 with the advantage of an additional ply.
BUT, when I forced 8.exd5, play immediately turned out better than
8.Qxd5.

And this brings me back to my early question: why are we turning to
computers for analysis?  Ok, another data point, why not.  But now I
wish I could turn the problem over to a "reasonable" computer that
could give a few more ply on each search.

Here are parallel logs for a few moves (100 points = 1 pawn; negative
numbers favor Black; column after Score gives ply; I discarded the
suggested lines, which are generally followed by the program anyway).


Move               Score Ply

  7. dxe4            -84   7
  7.       hxg5      -82   7
  8. Qxd5            -66   7             8. exd5
  8.       Na6       -83   8             8.       Qd7       -80   8
  9. Qxc6+           -74   7             9. Bxg5            -66   7
  9.       bxc6     -148   9             9.       a6        -44   7
 10. Nd4            -129   8            10. Nc3             -48   7
 10.       Nb4      -147   8            10.       e5        -63   8
 11. a3             -119   8            11. dxe6            -46   7
 11.       e5       -153   9            11.       Qxe6+     -41   8
 12. c3             -140   8            12. Be2             -30   8
 12.       exd4     -145   8            12.       Nf6       -33   7
 13. axb4           -158   8            13. Qd3             -17   7
 13.       g4       -148   7            13.       c5        -43   6
 14. Bf4            -142   8            14. Bxf6             34   7
 14.       dxc3     -115   8            14.       Qxf6       24   7
 15. bxc3           -137   8            15. Nd5             -49   7
 15.       Bb7       -71   7            15.       Qd6        26   7
 16. Bxc7            -82   8            16. O-O-O            32   6
 16.       Nf6       -75   8            16.       Be7        35   7
 17. f3              -61   8            17. Qe4              60   7
 17.       Be7       -77   8            17.       Nc6       110   7
 18. Bc4             -71   7            18. Nb6             116   7
 18.       gxf3      -72   7            18.       Qh6+       40   7
 19. gxf3            -85   8            19. f4               44   8
 19.       Bd8       -27   7            19.       Rb8        44   7
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