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Subject: Re: try this position too! (more)

Author: martin fierz

Date: 22:42:55 10/17/02

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On October 18, 2002 at 00:47:48, Robert Hyatt wrote:

>On October 18, 2002 at 00:35:38, Robert Hyatt wrote:
>
>>On October 17, 2002 at 23:35:58, martin fierz wrote:
>>
>>>On October 17, 2002 at 04:51:28, Christophe Drieu wrote:
>>>
>>>>[D] 8/4k3/4p3/pp5p/6p1/2P2rP1/PPK2R1P/8 w - - 0 1
>>>>
>>>>Rxf3 !
>>>
>>>for all those who find Rxf3 in the first position, how about a slightly modified
>>>version:
>>>
>>>[D] 8/4k3/4p3/1p5p/p5p1/2P2rP1/PPK2R1P/8 w - - 0 1
>>>
>>>this time, Rxf3 will not win any more. if your static eval just more or less
>>>"randomly" thinks the first position is a win for white after Rxf3, does it also
>>>realize that the second one is not a win?
>>>
>>>i think this also explains quite well why the first position is difficult for
>>>engines: since the second, *very* similar position is not winning, you will have
>>>some trouble to formulate a rule why the first is and the second is not winning
>>>:-)
>>>
>>>aloha
>>>  martin
>>
>>\
>>Crafty for the first position, static eval is +.63, for the second -.30....  It
>>likes Rf3 in
>>the second but the score is only slightly positive for white.  At 11 seconds it
>>drops to
>>draw score, and at 48 seconds, Rf3 is slightly negative.  At that point, it
>>still plays the
>>move as best, but the score hovers around the draw score, just on either side...
>
>
>I should note that at depth=18,. Rf3 failed high to +1.0...  whether that is
>significant or
>not is a question for another day, it is late here.  :)
>
>               17     5:45   0.00   1. Rxf3 gxf3 2. Kd3 e5 3. b3 axb3 4.
>                                    axb3 e4+ 5. Ke3 Kd6 6. h3 Kd5 7. Kf2
>                                    Ke5 8. Ke3 Kd5
>               17->  11:52   0.00   1. Rxf3 gxf3 2. Kd3 e5 3. b3 axb3 4.
>                                    axb3 e4+ 5. Ke3 Kd6 6. h3 Kd5 7. Kf2
>                                    Ke5 8. Ke3 Kd5
>               18    12:24     ++   1. Rxf3!!
>               18    14:55   0.91   1. Rxf3 gxf3 2. Kd3 e5 3. b3 e4+ 4.
>                                    Ke3 Kf6 5. bxa4 bxa4 6. Kf2 Ke5 7.
>                                    h3 a3 8. Ke3 Kf5 9. c4 Ke5 10. c5 Kd5

either crafty is missing something or i&fritz are - why not 4. ...axb3 and Ke6?

aloha
  martin



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