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Subject: Re: Crafty-Fritz

Author: jeff

Date: 19:19:24 10/29/97

Go up one level in this thread


On October 29, 1997 at 20:31:20, Robert Hyatt wrote:

>On October 29, 1997 at 19:04:28, jeff wrote:
>
>>On October 29, 1997 at 08:56:57, Robert Hyatt wrote:
>>
>>>On October 28, 1997 at 19:42:37, Willie Wood wrote:
>>>
>>>>Bob,
>>>>
>>>>Congrats on your standing after round 5.
>>>>
>>>>Did you happen to look at 35 Bd8 in round 2?  A couple programs I have
>>>>show Be3 as the move.  Was there some time pressure?
>>>>
>>>>WW
>>>
>>>Had a chance to study this this morning.  Be3 leads to a worse position,
>>>Crafty thinks.  here is the PV:
>>>
>>> 11->   1:18  -0.175   Be3 Ke6 Rxc7 Nxb7 Rc6+ Kf7 Kf1 Rh1+
>>>                       Ke2 Rxd1 Kxd1 Nxa5 Rc7+ Ke6 b4
>>>
>>>while Bd8 looks better (to crafty):
>>>
>>> 11->   1:20   0.087   Bd8 Nb5 Bh4 Nd4 Rc5 Nxb7 Rxe5 Kd6 Rb5
>>>                       Kc6 Rb6+ Kc7 Rxd4 Nxa5
>>>
>>>shallower depths like Be3.  I suspect crafty searched to depth=13 in
>>>this position on the alpha...
>>
>>
>>Does anyone think that crafty's 33. Bg5 was strange?  BxPb2 looks much
>>better.  Maybe something is broken, Hyatt?  Maybe it's me.
>
>
>"broken" is probably the wrong term, as Bxb7 gets worse and worse as the
>search goes deeper:
>                7     1.20   1.304   Bxb7 e4 Rxd6+ Kxd6 Bf4+ Ke7 Bg5+
>Kd6
>                                     Rc6+ Ke5 Bxa6
>                7->   1.28   1.304   Bxb7 e4 Rxd6+ Kxd6 Bf4+ Ke7 Bg5+
>Kd6
>                                     Rc6+ Ke5 Bxa6
>                8     1.85      --   Bxb7
>                8     2.63   0.923   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2
>Rxc1
>                                     Rxc1 Nc7
>                8->   2.71   0.923   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2
>Rxc1
>                                     Rxc1 Nc7
>                9     4.50   0.842   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2
>Rxc1
>                                     Rxc1 Nc5 Bc8
>                9->   4.58   0.842   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2
>Rxc1
>                                     Rxc1 Nc5 Bc8
>               10    10.02   0.895   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2 g5
>                                     Bxa6 Ra7 Bc8 Rxa5 Bxg5
>               10->  10.11   0.895   Bxb7 e4 Rxd6+ Kxd6 Kf1 Rh1+ Ke2 g5
>                                     Bxa6 Ra7 Bc8 Rxa5 Bxg5
>               11    17.56      --   Bxb7
>               11    28.79   0.225   Bxb7 e4 Rxd6+ Kxd6 Kf1 g5 Bxa6 Ra7
>                                     Bc8 Rxa5 Bxg5 Rd5
>               11->  28.83   0.225   Bxb7 e4 Rxd6+ Kxd6 Kf1 g5 Bxa6 Ra7
>                                     Bc8 Rxa5 Bxg5 Rd5
>
>while Bg5 doesn't do this:
>
>                7->   0.58   0.855   Bg5 R2h5 Bxb7 Rxg5 Bxa6 e4 b4
>                8     1.23   0.847   Bg5 R2h5 Bxb7 Rxg5 Bxa6 Rh6 Bb5+
>Ke6
>                                     Rc6
>                8->   1.31   0.847   Bg5 R2h5 Bxb7 Rxg5 Bxa6 Rh6 Bb5+
>Ke6
>                                     Rc6
>                9     3.67   0.940   Bg5 R2h5 Bxb7 Ke6 Bh4 g5 Rc6 Rxb7
>Rdxd6+
>                                     Kf7 Rxa6 gxh4
>                9->   3.75   0.940   Bg5 R2h5 Bxb7 Ke6 Bh4 g5 Rc6 Rxb7
>Rdxd6+
>                                     Kf7 Rxa6 gxh4
>               10     8.67   1.010   Bg5 R2h5 Bxb7 Rxg5 Bxa6 Rgh5 Bb7
>Rh2
>                                     Bc8+ Ke7 Rc7+ Kd8
>               10->   8.75   1.010   Bg5 R2h5 Bxb7 Rxg5 Bxa6 Rgh5 Bb7
>Rh2
>                                     Bc8+ Ke7 Rc7+ Kd8
>               11    22.35   1.072   Bg5 R2h5 Bxb7 Rxg5 Rc6 Rh6 Rxa6 e4
>                                     Bd5 Ke7 b4
>               11->  22.47   1.072   Bg5 R2h5 Bxb7 Rxg5 Rc6 Rh6 Rxa6 e4
>                                     Bd5 Ke7 b4
>
>Now as to "is this a horizon effect problem?" That I don't know yet.
>But
>I can see why Bg5 was played here based on comparing the two scores...



I'm sorry...I didn't backup my post.  Crafty 12.6 chooses Bxb7 through
14 ply with around a +1.3 score.  I was wondering what was going on
here?  I ran wcrafty on a PPRO 200 under win95 using the default
settings for 30 minutes.  I chose 12.6 due to its "solid" reputation.



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