Author: Bernhard Bauer
Date: 22:22:41 06/06/00
Go up one level in this thread
On June 06, 2000 at 16:00:17, Dann Corbit 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 think this is a good example to show that "best moves" in EPD test positions
>are only "best moves" for a certain depth unless a checkmate is found.
>
>For instance, a computer of ten years ago would be doing very well to find Nxf7.
> But upon searching deeper, it seems g4 might be better. After an even deeper
>search, e4 looks better.
>
>I would not be surprised in the least if an even deeper search turned up
>something else, including one of the previous moves.
>
>In short, I think that best moves are valid to some particular ply depth if they
>have the appropriate evaluation. But until we definitely find a checkmate,
>there is always a possibly better move -- perhaps hidden by NULL move or some
>such.
In an overnight computation my modified Crafty gave:
(3) 11-> 41.87 -0.05 1. Nxf7 Qd7 2. Nh6 cxd4 3. exd4 b5
4. Nf5+ Kg8 5. Nh6+ Kf8 6. Qf3 Kg7
7. Nf5+
(2) 12 1:07 -0.02 1. Nxf7 Qd7 2. Nh6 Rad8 3. h3 cxd4
4. Nf5+ Kg8 5. Qg6+ Bg7 6. Nxd4 Rc8
7. Rfc1
(4) 12-> 2:51 -0.02 1. Nxf7 Qd7 2. Nh6 Rad8 3. h3 cxd4
4. Nf5+ Kg8 5. Qg6+ Bg7 6. Nxd4 Rc8
7. Rfc1
(3) 13 4:05 -0.09 1. Nxf7 Qd7 2. Nh6 Kf8 3. Qf3 Ke7 4.
Ng4 Bg7 5. Qf4 Rf8 6. Qg5+ Kd6 7. dxc5+
bxc5 8. Rd3
13 14:55 0.06 1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
Kg8 5. Qh6 f6 6. gxf6 Nb4 7. Qg6+ Kf8
8. dxc5 bxc5
13-> 16:34 0.06 1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
Kg8 5. Qh6 f6 6. gxf6 Nb4 7. Qg6+ Kf8
8. dxc5 bxc5
14 20:11 0.08 1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
Kg8 5. Qh6 f6 6. gxf6 Re6 7. Qg7+ Qxg7+
8. fxg7 Rg6+ 9. Bg2 Rxg7 10. Nxg7 Kxg7
11. dxc5 bxc5
14-> 24:22 0.08 1. g4 Qd7 2. g5 Bd8 3. Bh3 Qc7 4. Nf5+
Kg8 5. Qh6 f6 6. gxf6 Re6 7. Qg7+ Qxg7+
8. fxg7 Rg6+ 9. Bg2 Rxg7 10. Nxg7 Kxg7
11. dxc5 bxc5
15 40:30 0.13 1. g4 Rh8 2. Qxf7+ Kxh6 3. f4 Rg8 4.
Qxb7 Nb4 5. g5+ Bxg5 6. fxg5+ Qxg5
7. Rf2 Raf8 8. h4 Qxh4 9. Rxf8 Rxf8
10. Qxa7
15-> 60:25 0.13 1. g4 Rh8 2. Qxf7+ Kxh6 3. f4 Rg8 4.
Qxb7 Nb4 5. g5+ Bxg5 6. fxg5+ Qxg5
7. Rf2 Raf8 8. h4 Qxh4 9. Rxf8 Rxf8
10. Qxa7
16 66:17 -- 1. g4
16 93:02 -0.47 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. Rd2 cxd4 10.
Rg3
16 209:05 -0.34 1. Bh3 Qc7 2. Nf5+ Kg8 3. Nh6+ Kf8
4. Nf5 Bg7 5. Nxg7 Kxg7 6. Qg5+ Kf8
7. Qh6+ Ke7 8. Qg5+ f6 9. Qg7+ Kd8
10. Qxf6+ Qe7
16 356:58 -0.15 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
10. Bd5+
16 541:40 0.00 1. Nxf7 Qd7 2. Nh6 Kf8 3. g4 Bg7 4.
g5 Bxh6 5. Qxh6+ Qg7 6. Qd6+ Re7 7.
h4 cxd4 8. Qf4+ Qf7 9. Qxd4 Nc5
So you are right. Crafty gives another move, the same Nxf7 as before.
Kind regards
Bernhard
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