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Subject: Re: Zappa 1.1

Author: Ed Schröder

Date: 11:25:17 09/15/05

Go up one level in this thread

On September 15, 2005 at 14:07:05, Robert Hyatt wrote:

>On September 15, 2005 at 07:21:19, Ed Schröder wrote:
>
>>On September 15, 2005 at 06:43:22, Gian-Carlo Pascutto wrote:
>>
>>>On September 15, 2005 at 06:26:30, Ed Schröder wrote:
>>>
>>>>On September 15, 2005 at 04:30:38, Mark Young wrote:
>>>>
>>>>>On September 14, 2005 at 17:05:59, Ernst Walet wrote:
>>>>>
>>>>>>Because Zappa 1.1 is SMP and 64 bit, I gave it a try and was pleasant suprised.
>>>>>>One of my favourite chess positions is this one, where Kasparov played Rxd4.
>>>>>>How do other engines do? If your engine finds it please give it a couple of more
>>>>>>plies to see if it holds it.
>>>>>
>>>>>The better test for the engine in this position, is to see when the program see
>>>>>that Rxd4 is not winning. Since Rxd4 is only a draw with best play.
>>>>>This is why many programs will not play Rxd4, or drop the move with a longer
>>>>>search.
>>>>
>>>>1. Rxd4 cxd4 2. Re7+ Kb6 3. Qxd4+ Kxa5 4. b4+ Ka4 5. Ra7 Bb7 6. Rxb7 Qxd5 7. Rb6
>>>>1-0
>>>
>>>I always thought that simply 1. .. Kb6 was never refuted?
>>
>>You are absolutely right, missed that one. But I would like to see the engine
>>that plays 1..Kb6
>>
>>Hmmm...
>>
>>Ed
>
>
>Here is one:  (this on my dual xeon, searching around 2M nodes per second.  WCCC
> opteron would be 8x faster...
>
>               12    13.94  -1.77   1. ... cxd4 2. Re7+ Kb6 3. Qxd4+ Kxa5
>                                    4. Qc3+ b4 5. axb4+ Qxb4 6. Qc7+ Ka4
>                                    7. b3+ Ka3 8. Qe5 Qb6 9. Qb2+ Kb4 10.
>                                    c3+ Kc5 11. Qf2+ Kd6 12. Qxb6+ Kxe7
>                                    13. c4
>               12->  20.05  -1.77   1. ... cxd4 2. Re7+ Kb6 3. Qxd4+ Kxa5
>                                    4. Qc3+ b4 5. axb4+ Qxb4 6. Qc7+ Ka4
>                                    7. b3+ Ka3 8. Qe5 Qb6 9. Qb2+ Kb4 10.
>                                    c3+ Kc5 11. Qf2+ Kd6 12. Qxb6+ Kxe7
>                                    13. c4 (s=2)
>               13    26.64     +1   1. ... cxd4
>               13    34.01  -0.01   1. ... cxd4 2. Re7+ Kb6 3. Qxd4+ Kxa5
>                                    4. b4+ Ka4 5. Qc3 Qxd5 6. Qc7 Qd1+
>                                    7. Kb2 Qd4+ 8. Kb1 Qd1+
>               13     2:46  -0.31   1. ... Kb6 2. Nb3 Bxd5 3. Qxd6+ Rxd6
>                                    4. Rd2 Rhd8 5. Red1 Ne8 6. f4 Bf3 7.
>                                    Rxd6+ Nxd6 8. Rd3 Be4 9. Rd2 a5
>
>Plays Kb6 to avoid a perceived repetition after cxd4...

Yep mine plays it too. New Challenge, which engine finds 5.Ra7!!

This after: 1. Rxd4 cxd4 2. Re7+ Kb6 3. Qxd4+ Kxa5 4. b4+ Ka4 5. Ra7 Bb7 6. Rxb7
Qxd5 7. Rb6

Ed

• Re: Zappa 1.1 Ernst Walet 00:16:55 09/16/05
• Re: Zappa 1.1 Vladimir Xern 16:38:35 09/15/05
• Re: Zappa 1.1 Andreas Guettinger 14:03:28 09/15/05
  • Re: Zappa 1.1 Eelco de Groot 14:52:44 09/15/05
    • Re: Zappa 1.1 Vincent Lejeune 15:26:51 09/15/05
      • Re: Zappa 1.1 Ed Schröder 00:27:32 09/16/05
        • Re: Zappa 1.1 Vincent Lejeune 01:41:49 09/16/05
      • Pro Deo 1.1 Vulcan finds 28.Ra7! Eelco de Groot 19:19:44 09/15/05
        • Re: Pro Deo 1.1 Vulcan finds 28.Ra7! Eelco de Groot 19:20:55 09/15/05
  • Re: Zappa 1.1 Uri Blass 14:07:11 09/15/05
    • Re: Zappa 1.1 Uri Blass 14:49:59 09/15/05
    • Re: Zappa 1.1 Andreas Guettinger 14:34:52 09/15/05

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