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Subject: Re: A crafty try with a crafty question

Author: Pete R.

Date: 09:15:07 06/07/00

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On June 07, 2000 at 04:16:50, blass uri wrote:

>On June 06, 2000 at 15:10:07, pete wrote:
>
>>On June 05, 2000 at 19:18:56, Pete R. wrote:
>>
>>>Here is the diagram Mr. Uri posted last week:
>>>
>>>[D]r2qr3/pb3pk1/np3b1N/2pp3Q/3P4/1PR1P1P1/P4PBP/5RK1 w - - 0 1
>>>
>>>I let Fritz 5.32 run the weekend on it, and after a great deal of
>>>thought it decided the best move is...1. e4!!.
>>>
>>>Analysis by Fritz 5.32:
>>>
>>>-+  (-2.94) 1.dxc5 Bxc3 2.Nxf7   00:00:00
>>>=  (-0.25) 1.Nxf7   00:00:00
>>>²  (0.31) 1.Nxf7   00:00:00
>>>=  (0.25) 1.Nxf7 Qe7   00:00:00
>>>³  (-0.47) 1.Nxf7 Qe7 2.Ne5   00:00:00
>>>³  (-0.44) 1.Rfc1   00:00:00
>>>³  (-0.41) 1.Rfc1 Qd7 2.Nf5+ Kg8   00:00:00
>>>³  (-0.37) 1.Rd3   00:00:00
>>>³  (-0.34) 1.Rd3 Qd7 2.dxc5 Nxc5 3.Nf5+ Kg8   00:00:00
>>>³  (-0.31) 1.Qxf7+   00:00:00
>>>²  (0.50) 1.Qxf7+ Kxh6 2.Qxb7 Nb4   00:00:00
>>>=  (0.06) 1.Qxf7+ Kxh6 2.Qxb7 Nb4 3.a3   00:00:00
>>>=  (0.09) 1.Nxf7   00:00:00
>>>²  (0.44) 1.Nxf7 Qd7 2.Ne5 Bxe5   00:00:00
>>>²  (0.53) 1.Nxf7 Qe7 2.Nh6 Rh8 3.Nf5+ Kf8   00:00:00
>>>²  (0.56) 1.Nxf7 Qd7 2.Nh6 Kf8 3.Nf5 Rac8   00:00:00
>>>²  (0.47) 1.Nxf7 Qe7 2.Nh6 Bc8 3.Qxd5 Nc7 4.Nf5+ Bxf5 5.Qxf5 cxd4   00:00:00
>>>²  (0.69) 1.Nxf7 Qc7 2.Nh6 Rf8 3.Nf5+ Kg8 4.f4 Rae8 5.Nh6+ Kg7   00:00:03
>>>±  (0.75) 1.Nxf7 Qc7 2.Nh6 Rh8 3.Nf5+ Kf8 4.Qg6 Bg7 5.Rd1 Rd8   00:00:08
>>>²  (0.69) 1.Nxf7 Qc7 2.Nh6 Rad8 3.Nf5+ Kf8 4.a3 Qf7 5.Qxf7+ Kxf7   00:00:24
>>>±  (0.81) 1.Nxf7 Qc7 2.Nh6 Rh8 3.Nf5+ Kf8 4.Qg6 Bg7 5.Bxd5 Bxd5   00:01:27
>>>±  (0.81) 1.Nxf7 Qc7 2.Nh6 Rf8 3.g4 Kh8 4.Nf7+ Kg8 5.Qg6+ Bg7   00:03:49
>>>±  (0.84) 1.g4   00:28:08
>>>±  (1.06) 1.g4 Rh8 2.Qxf7+ Kxh6 3.f4 Rg8 4.g5+ Bxg5 5.Qxb7 Nc7   01:22:25
>>>±  (1.00) 1.g4 Rh8 2.Qxf7+ Kxh6 3.f4 Rg8 4.Qxb7 Nc7 5.h3 Bg7   01:41:17
>>>²  (0.50) 1.g4 Rh8 2.Qxf7+ Kxh6 3.f4 Rg8 4.Qxb7 Nb4 5.g5+ Bxg5   04:56:05
>>>²  (0.53) 1.Nxf7   05:04:04
>>>²  (0.69) 1.Nxf7 Qd7 2.Ne5 Bxe5 3.dxe5 Qe6 4.f4 Rh8 5.Qg5+ Kf7   09:27:46
>>>±  (0.72) 1.e4   16:27:07
>>>±  (0.78) 1.e4 dxe4 2.g4 Rh8   22:38:47
>>>±  (0.84) 1.e4 dxe4 2.g4 Rh8 3.Qxf7+ Kxh6 4.Qxb7 Nc7 5.Rh3+ Kg7   37:03:44
>>>
>>>Final depth reached is 16 ply.  As you can see it took 16.5 hours on a PII
>>>400 to decide on 1.e4!!.  According to my analysis (although not completely
>>>exhaustive) I do think this is the best move and white likely wins in all
>>>lines:
>>>
>>>1. e4!! dxe4 2. g4 Rh8
>>>
>>>other tries:
>>>
>>>  A) 2...Bc8 3. Qxf7+ Kxh6 4. Rh3+ Bh4 5. Qh5+ Kg7 6. Rxh4 Qf6
>>>     7. Qxe8 Qxh4 8. Re1 +-.
>>>
>>>  B) 2...Bh4 3. Nf5+ Kg8 4. g5 Qd7 5. g6 fxg6 6. Qxg6+ Kf8 7. Rg3 +-.
>>>
>>>  C) 2...Bg5 3. Nf5+ Kf6 4. f4 exf3 5. h4 Bd2 6. Bxf3 Rh8 7. g5+ Ke6
>>>     8. Re1+ Bxe1 9. Re3+ +-.
>>>
>>>3. Qxf7+ Kxh6 4. Rh3+ Bh4 5. Qxb7 and white wins:
>>>
>>>       a) 5...Nc7 6. dxc5 bxc5 (...Kg7 7. cxb6 axb6 8. Rc3 Rc8
>>>            9. Rfc1 Bxf2+ 10. Kxf2 +-) 7. Rxh4+ Qxh4 8. Qc6+ Kg7
>>>          9. Qxc7+ Kg8 10. h3 +-.
>>>
>>>       b) 5...cxd4 6. f4 Nc7 7. Qxe4 Kg7 8. Qe5+ Bf6 9. Rxh8 Kxh8
>>>          10. Qh5+ Kg8 11. Qg6+ Kf8 12. g5 +-.
>>>
>>>       c) 5...Qg5 6. Qxa6 Qxg4 (...Rag8 7. f3 cxd4 8. Qc4 e3 9. Rc1 Rg6
>>>            10. Qxd4 Rd8 11. Qe4 +-) 7. f3 exf3 8. Rfxf3 Rae8 9. Qf1 +-.
>>>
>>>So black is dead meat after 1...dxe4. Black's only serious alternative is
>>>
>>>1....Rh8, leading to the line 1. e4 Rh8 2. Qxf7+ Kxh6 3. Rf3 Rf8
>>>4. Qxb7 and now Nb4 appears best for black.  I've analyzed a number of
>>>continuations and have not been able to prove an ironclad win for white
>>>in all of them, but white definitely has the upper hand and black is
>>>merely defending.
>>
>>I think your analysis is quite convincing ; e4 seems to be the best move and
>>requires a very deep search . Here some output from Crafty17.10 :
>>
>>12    15:51   0.06   1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
>>                                    Kg8 5. Qh6 f6 6. gxf6 Re6 7. Ne7+ Rxe7
>>                                    8. Qg6+ Rg7 9. fxg7 Qxg7 10. Qxg7+
>>                                    Kxg7 11. dxc5 bxc5
>>               12->  19:05   0.06   1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
>>                                    Kg8 5. Qh6 f6 6. gxf6 Re6 7. Ne7+ Rxe7
>>                                    8. Qg6+ Rg7 9. fxg7 Qxg7 10. Qxg7+
>>                                    Kxg7 11. dxc5 bxc5
>>               13    37:59     --   1. g4
>>               13    42:36  -0.48   1. g4 Rh8 2. Qxf7+ Kxh6 3. Qxb7 Nb4
>>                                    4. f4 Rg8 5. g5+ Bxg5 6. fxg5+ Qxg5
>>                                    7. Rf2 Raf8 8. e4 Qg4 9. Rg3 Qd1+ 10.
>>                                    Rf1 Rxf1+ 11. Bxf1 Rxg3+ 12. hxg3 Qxd4+
>>               13    72:19  -0.22   1. e4 dxe4 2. g4 Bc8 3. Qxf7+ Kxh6
>>                                    4. Rh3+ Bh4 5. Rxh4+ Qxh4 6. Qxe8 Kg7
>>                                    7. Qe5+ Kf8 8. Qf4+ Kg8 9. Bxe4 Rb8
>>               13   111:18   0.00   1. Nxf7 Qd7 2. Nh6 Kf8 3. Qf3 Ke7 4.
>>                                    Qf4 Qc7 5. Qf5 Qd7 6. Qf4
>>         (4)   13-> 137:08   0.00   1. Nxf7 Qd7 2. Nh6 Kf8 3. Qf3 Ke7 4.
>>                                    Qf4 Qc7 5. Qf5 Qd7 6. Qf4
>>         (3)   14   141:49  -0.03   1. Nxf7 Qd7 2. Nh6 Kf8 3. Ng4 Bg7 4.
>>                                    Nh6 Rab8 5. h3 cxd4 6. exd4 Bf6 7.
>>                                    Nf5 Rbc8 8. Rfc1
>>         (2)   14   264:24   0.30   1. e4 dxe4 2. g4 Bc8 3. Qxf7+ Kxh6
>>                                    4. Rh3+ Bh4 5. Qh5+ Kg7 6. Rxh4 Rb8
>>                                    7. Bxe4 Qxh4 8. Qxh4 Rxe4 9. Qg5+ Kh7
>>                                    10. Qh5+ Kg7
>>
>>
>>I didn't want to wait longer and stopped here but I'd expect a fail high on e4
>>at ply 15 .
>>
>>What is strange to me is that Dr Hyatt has posted that Crafty17.11 sticks to
>>Nxf7 right from the start until end of ply 14 . This is really a major change to
>>17.10 and the result seems to be not too good .
>
>I do not know if this is a major change.
>The question is if parallel crafty 17.10 get the same results.
>
>I am also not sure if e4 is the best move and it is possible that Nxf7 is the
>best move.

I am not sure either, because of the line 1. e4 Rh8 2. Qxf7+ Kxh6 3. Rf3 Rf8
4. Qxb7 Nb4.  But 1...Rh8 is the only response for black that holds against e4,
so one could say that in a game 1. e4 is best because black has only one way to
survive. I.e. if the real truth of the position is that black can draw the game
against both 1. e4 and 1. Nxf7, then the most demanding path to that draw can be
said to be best even if there is no forced win.



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