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Subject: Re: Interesting avoid move position

Author: Geoff Westwood

Date: 13:34:47 02/18/04

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Hi Robert

Yep, agreed black is probably lost by this stage anyways. As a matter of
interest what does Crafty do when a fail low occurs ? I am guessing it increases
its thinking time ? How much does it increase by ?

        Regards Geoff





On February 18, 2004 at 16:12:52, Robert Hyatt wrote:

>On February 18, 2004 at 16:08:41, Geoff Westwood wrote:
>
>>Hi
>>
>>This position is from a post by Gábor Szõts. ElChinito_325 (White) v  Abrok 5.0
>>(Black)
>>
>>[D]2q2r1k/2P2ppp/2R1p3/3bN3/rp3B2/1n4Q1/1P4PP/3R2K1 b - - 0 26
>>
>>Abrok lost quickly by grabbing the juicy looking rook Bxc6. My program also
>>staggered around for 90 seconds trying to find a half decent move for black.
>>
>>CM9000 took about 10 secs to discover that taking the Rook is very bad
>>
>>At least my program and CM9000 both eventually agree that the best move is Ra1.
>>Having seen this example I think I should maybe go and add a thinking time
>>extension for a fail low, I hadn't bothered until now. It might help me stop
>>making some particularly dumb moves.
>
>I think this is trouble no matter what move you try...
>
>                9->   4.19   0.88   1. ... Bxc6 2. Bh6 gxh6 3. Rd8 Ra1+
>                                    4. Kf2 Rf1+ 5. Kxf1 Qa6+ 6. Kf2 Qb6+
>                                    7. Qe3 Qxc7 8. Rxf8+ (s=2)
>               10     4.51     --   1. ... Bxc6
>               10     5.36   2.83   1. ... Bxc6 2. Bh6 gxh6 3. Rd8 Ra1+
>                                    4. Kf2 Be8 5. Rxc8 Nd2 6. Nxf7+ Rxf7+
>                                    7. Ke2 Re7 8. Kxd2
>               10     8.25   1.68   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Re8 6. Qxf7 b3
>               10->  10.28   1.68   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Re8 6. Qxf7 b3
>                                    (s=4)
>               11    10.51     --   1. ... Ra1
>               11    10.87   2.08   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Re8 6. Qxf7 b3
>                                    7. Rf1 (s=3)
>               11->  19.81   2.08   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Re8 6. Qxf7 b3
>                                    7. Rf1 (s=14)
>               12    21.04   2.13   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Rg8 6. Qxf7 b3
>                                    7. Ra3 Bd5 (s=13)
>               12->  42.18   2.13   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Rg8 6. Qxf7 b3
>                                    7. Ra3 Bd5 (s=12)
>               13    46.39   2.38   1. ... Ra1 2. Rxa1 Nd4 3. Qf2 Nxc6
>                                    4. Nxc6 Bxc6 5. Bd6 Re8 6. Qxf7 e5
>                                    7. Rc1 Qa8 8. Rc5 Bxg2 9. Bxe5 (s=11)
>
>My dual xeon 2.8 drops Bxc6 quickly, needing 8.25 seconds to switch to Ra1.  But
>Ra1 doesn't look all that rosey either...
>
>>
>>
>>Ply  Eval   Time      Nodes   Principle Variation
>> 1    195      0        100   d5c6 e5c6
>> 2    195      0        927   d5c6 e5c6
>> 3    200      0       2611   d5c6 e5c6 b3c5
>> 4-   160      1      17178   d5c6
>> 4    104      4      36557   f7f6 f4h6 g7h6 d1d5 e6d5 g3b3
>> 5    119     10      90837   f7f6 c6b6 f6e5 b6b8 e5f4 b8c8 f4g3 c8f8
>> 6    119     28     203744   f7f6
>> 7     91     82     619528   f7f6 c6b6 f6e5 f4e5 f8g8 b6b8 c8a6 d1d5 e6d5 g3b3
>> 8     81    203    1452043   f7f6 c6b6 f6e5 b6b8 e5f4 b8c8 f8c8 g3f4
>> 9-    41    862    6294138   f7f6
>> 9    -30   2239   15651825   d5c6 e5f7 h8g8 d1d8 a4a1 g1f2 b3c1 d8c8 f8c8 f7h6
>>g8h8 h6f7 h8g8
>>10-   -70   5362   37011086   d5c6
>>10   -105   8768   60476406   a4a6
>>11   -119  15540  106180448   a4a1 d1a1 b3a1 c6d6 c8c7 d6d7 c7c8 e5f7 f8f7 d7f7
>>c8g8 f7c7
>>12   -109  25546  173819086   a4a1 d1a1 b3a1 c6d6 c8c7 d6d7 c7c8 e5f7 f8f7 d7f7
>>c8g8 f7c7 a1b3
>>
>>         Geoff



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