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

Author: Robert Hyatt

Date: 21:47:48 10/17/02

Go up one level in this thread


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




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