Author: Robert Hyatt
Date: 10:47:02 02/18/98
Go up one level in this thread
On February 18, 1998 at 10:55:14, Albert Silver wrote:
>I had commented (subject to corrections of course) the position in CA
>3.02 and had then exported it into PGN format. Unfortunately it seems
>that it made things unclear, so by request here are just the moves:
>
>
>[Event "Campeonato Brasileiro Absoluto 1997 "]
>[Site "Rio de Janeiro"]
>[Date "1998.02.??"]
>[Round "10"]
>[White "Wellington Rocha"]
>[Black "Darcy Lima"]
>[Result "1-0"]
>[ECO "D21"]
>[WhiteELO "2325"]
>[BlackELO "2475"]
>[Annotator ""]
>[Source ""]
>[Remark ""]
>
>1.d4 d5 2.c4 dc4 3.Nf3 c5 4.e3 cd4 5.Bc4 Qc7 6.Qb3 e6 7.ed4 Nc6
>8.0-0 a6 9.Bd2 Nf6 10.Bd3 Be7 11.Nc3 0-0 12.Rac1 Rd8 13.Ne4 Qb8
>14.Rfe1 Bd7 15.Nc5 Be8 16.Be3 Ra7 17.a3 Nd5 18.Bb1 a5 19.Qd3
>g6 20.h4 b6 21.Ne4 Nf6 22.Nf6+ Bf6 23.Qe4 Ne7 24.h5 Nd5 25.Bh6
>Ra8 26.Ne5 Qd6 27.hg6 hg6 28.Qg4 Bg7 29.Qh3 Bh6 30.Qh6 Qf8 31.Qh4
>Qe7 32.Qg3 Rac8 33.Ba2 Rc1 34.Rc1 Qd6 35.Qh4 Qe7 36.Qg3 Qd6 37.Qf3
>Kg7 38.g3 Ne7 39.Rd1 Nf5 40.Qc3 Kg8 41.d5 Qc5 42.Qc5 bc5 43.Rc1
>ed5 44.Rc5 a4 45.Rd5 Rb8 46.Rd2 Kg7 47.g4 Nh4 48.Kh2 Rb5 49.Kg3
>Re5 50.Kh4 g5+ 51.Kg3 Re1 52.f3 Kf6 53.Kf2 Rc1 54.Ke3 Ke7 55.Bd5
>f6 56.Be4 Bb5 57.Rd4 Bd7 58.Bd3 Rh1 59.Be2 Rb1 60.Rb4 f5 61.Bd3
>f4+ 62.Ke2 Rh1 63.Be4 Kd6 64.Rd4+ Ke7 65.Kd2 Rh2+ 66.Kc3 Rh3
>67.Rd3 Be6 68.Kb4 Rh2 69.Ka4 Rb2 70.Ka5 Bc4 71.Rc3 Be2 72.Bc6
>Kd6 73.a4 Ke5 74.Bb5 Kd4 75.Ra3 Kc5 76.Be2 Re2 77.Rc3+ Kd4 78.Kb4
>Re3 79.Rb3 Re8 80.a5 Ra8 81.Ka4 Ra7 82.Ra3 Kc4 83.Ra1 Ra8 84.Re1
>Rd8 85.Rc1+ 1-0
>
>In the game above, I believe that had White played 29.Bxg7 Kxg7 he would
>have had the spectacular 30.Rc6!! at his disposition. Without going into
>excessive detail, the main ideas are: 30...Bxc6 31.Bxg6! or 30...Qe7
>31.Nxg6! and if 30...Qf8 31.Rxe6!
>
>
> Albert
Crafty didn't find this thru depth=12. I ran it on Cray Blitz, but I
had to use a very restrictive search time (5 seconds) to get into a
queue
that would give me results back reasonably quickly. Here's what it
found:
9-> 0:01 0.407 30. Rc6 Bxc6 31. Bxg6 Kf8 32. Bxf7
Ba4 33. Qg8+ Ke7 34. Qg7 Qc7 35. Nc6+
Kd6 36. Nxd8 Rxd8 37. Rxe6+ ...
the above means that at depth=9, around 1 second into the search, it
changed
to this move. At earlier searches it was flipping back and forth
between
Nc4 and Qh4, with scores in this same range. At ply=9, Qh4 was only
+.327
so Rc6 replaced it as best. The "..." at the end means the remainder of
the
PV, whatever it was, was truncated by a hash table hit (crafty now uses
<HT> to indicate this.) I have no idea how deep this went, because this
is
the "final" version of Cray Blitz with singular extensions and lots of
other
stuff as well. This is one of the faster positions I have seen it
search,
hitting just over 10M nodes per second on the T90 I used (actually which
a
friend of mine used, but I won't reveal his name to avoid disclosing
which
65 million dollar computer it was run on. :) )
Since Crafty didn't change to this (It liked Qh4 through depth 12 I
believe)
at depth=12, I don't know what it has to see. And we couldn't let CB
churn
on it for a while to see if this score will actually go up more, or if
there
is a defense by black that makes it "break even."
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