Author: Albert Silver
Date: 07:46:27 03/06/02
Go up one level in this thread
On March 06, 2002 at 10:29:18, Dann Corbit wrote:
>On March 06, 2002 at 00:55:15, Uri Blass wrote:
>
>>On March 05, 2002 at 23:19:39, Terry McCracken wrote:
>>
>>>On March 05, 2002 at 15:27:58, Dann Corbit wrote:
>>>
>>>>On March 05, 2002 at 13:35:06, Uri Blass wrote:
>>>>
>>>>>On March 05, 2002 at 11:43:35, Dann Corbit wrote:
>>>>>
>>>>>>On March 04, 2002 at 17:43:29, Albert Silver wrote:
>>>>>>
>>>>>>>The following position occurred in Spassky-Beliavsky, Reykjavik, 1988
>>>>>>>
>>>>>>>2b1qrk1/5p1p/pBn3p1/1p2p3/4P2N/bBP1Q3/P4PPP/3R2K1 w - -
>>>>>>>
>>>>>>>Spassky found a tremendous move 25.Nxg6!! and won the game. I don't think any
>>>>>>>engines will have much luck with it but feel free to try it. I've analyzed it in
>>>>>>>detail and can verify that it is the strongest move and correct, so as a further
>>>>>>>challenge, see if you can find the *strongest* continuation after the possible
>>>>>>>defense: 25...hxg6 26.Qh6 Be6!?
>>>>>
>>>>>
>>>>>This defence was discussed by albert silver and by me
>>>>>
>>>>>25.Nxg6 hxg6 26.Qh6 Be6 27.Rd3 f5
>>>>>28.Rg3 Rf6 29.Rh3 Kf7 30.Qh7+ Kf8 31.exf5 Bxb3 32.axb3
>>>>>seems to be decisive for white
>>>>>
>>>>>Yace proved 1.20 pawns for white in the root position for Nxg6 based on some
>>>>>analysis that is based mainly on this line.
>>>>
>>>>The two lines (first the yace line, then the crafty 1 hr analysis:)
>>>>W B W B W B W
>>>>Nxg6 hxg6 Qh6 Be6 Rd3 f5 Rg3 Rf6 Rh3 Kf7 Qh7+ Kf8 exf5 Bxb3 axb3 c0 "seems to
>>>>be decisive for white";
>>>>Nxg6 hxg6 Qh6 Be6 Rd3 f5 Rh3 Kf7 Qh7+ Kf6 Qh4+ Kg7 Bxe6 Qxe6 exf5 Qg8 Qh6+ Kf6
>>>>fxg6 Ke6 Rd3 Qh8 Qd2 Kf6
>>>>
>>>>Agree out to Rg3 verses Rh3. So I went to Rg3 and analyzed what would happen
>>>>there:
>>>>[D]4qrk1/8/pBn1b1pQ/1p2pp2/4P3/bBP3R1/P4PPP/6K1 b - - acd 14; acn 546692901; acs
>>>>1001; c0 "after Nxg6 hxg6 Qh6 Be6 Rd3 f5 Rg3"; ce 82; pv Rf6 Rh3 Kf7 Bd5 Ke7 c4
>>>>Bb4 Qg7+ Qf7 Qh8 Qf8 Bxc6 Qxh8 Rxh8 Bxc4;
>>>>
>>>>I remain unconvinced that this line is better.
>>>
>>>Really? Without the use of a computer and bieng a bit of a tactician, and
>>>looking over the evidence by computers as well, I feel confident Nxg6!! is
>>>without a doubt the strongest continuation.
>>>
>>>I'm confident I could win with White after the tactical shot Nxg6!! against
>>>anyone!:o)
>>>
>>>Terry
>>
>>I only feel sure that Nxg6 is a clear advantage for white but I do not feel sure
>>that white has no alternative good move.
>>
>>Nxg6 seems to be the best move based on computer's analysis because it wins at
>>least a pawn.
>>
>>I do not feel sure that I could win the game after Nxg6 against the best
>>defence because being a pawn up is not enough to win and you need also to play
>>well later(there are cases when even playing well later does not help against
>>the best defence).
>
>Yes. I was not clear in my meaning. I did not mean to say that Nxg6 was not a
>good move. Only that I am not yet convinced it is better than all of the
>alternatives. In particular, Nf3 and c4 are both very promising.
If you can show they are better than the simple Nxg6 hxg6 Qh6 Be6 Rd3 Bc1 which
just dumps the pawn but may offer the best chances for a defense, I'll agree,
but otherwise the Nxg6 is stronger. Remember that even after returning with
Qxc1, White's initiative has hardly died, nor has Black improved his much worse
position in any way. As to any other move than Bc1, Black is a dead duck. See
the lines I have been swapping with Ed below.
Slater gave it to Crafty 18.13 for 10 hours, and it still preferred Nf3, but the
question is what it saw on Nxg6 hxg6 Qh6. The eval he posted was a mere +0.91,
whereas when I let Crafty think on Nxg6 hxg6 Qh6 Be6 Rd3 Bc1 for 12 plies, it
gave White at +1.80 or so, so it wasn't Bc1 that it saw as a defense. If it
thought Rd3 f5 was the defense, it simply didn't see enough.
Albert
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