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Subject: Re: cute position

Author: Anthony Cozzie

Date: 07:52:04 08/15/03

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On August 15, 2003 at 10:38:47, Uri Blass wrote:

>On August 15, 2003 at 10:27:44, Anthony Cozzie wrote:
>
>>On August 15, 2003 at 10:13:05, Uri Blass wrote:
>>
>>>On August 15, 2003 at 10:03:06, Anthony Cozzie wrote:
>>>
>>>>On August 15, 2003 at 09:56:35, Uri Blass wrote:
>>>>
>>>>>On August 15, 2003 at 08:36:00, Anthony Cozzie wrote:
>>>>>
>>>>>>[D]r4r1k/1b3p1p/pq3N1p/n3p2N/Pp6/3Bn3/1PP1Q1PP/R4R1K w - - 0 26
>>>>>>
>>>>>>1. Rg1 Rfc8 2. Bxh7 Qd4 3. Rab1
>>>>>> = (-0.89)      Depth: 5/12     00:00:00.25     40kN
>>>>>>1. Rg1 Rfd8 2. Rae1 Bxg2 3. Rxg2 Nxg2 4. Qxg2 Qg1 5. Rxg1
>>>>>> = (-1.00)      Depth: 6/16     00:00:00.70     153kN
>>>>>>1. Rg1 Rfd8 2. Rae1 Bxg2 3. Rxg2 Nxg2 4. Qxg2 Qb7 5. Rxe5 Qxg2
>>>>>> + (-0.70)      Depth: 7/19     00:00:01.36     377kN
>>>>>>1. Rg1 e4 2. Bxe4 Bxe4 3. Nxe4 f5 4. Nef6 Rfd8
>>>>>> = (-0.09)      Depth: 7/19     00:00:02.15     685kN
>>>>>>1. Rg1 e4 2. Bxe4 Bxe4 3. Nxe4 f5 4. Qxe3 Qxe3
>>>>>> = (0.00)       Depth: 8/23     00:00:03.48     1192kN
>>>>>>1. Rf2 e4 2. Bxe4 Bxe4 3. Nxe4 f5 4. Nef6 Rfc8 5. Qd3 Rd8
>>>>>> = (-0.04)      Depth: 9/30     00:00:20.53     7692kN
>>>>>>1. Rf3 Bxf3 2. Qxf3 Qd4 3. Re1 Qh4 4. g3 Nxc2
>>>>>> = (0.25)       Depth: 10/33    00:00:42.98     16634kN
>>>>>>1. Rg1 Qd4 2. Rae1 Nec4 3. Bxc4 Nxc4 4. Rd1 Qc5 5. Nd7 Nb6 6. Nxf8 Rxf8
>>>>>> = (0.43)       Depth: 11/39    00:01:25.00     33717kN
>>>>>>1. Rf3 Bxf3 2. Qxf3 Qd4 3. Re1 Qh4 4. g3 Nac4 5. gxh4 Ng4 6. Bxc4 Nf2
>>>>>> + (0.73)       Depth: 12/48    00:05:37.18     133815kN
>>>>>>1. Rf3 Nxg2 2. Qxg2 Rg8 3. Qe2 Rg5 4. Be4 Rc8 5. h4 Rg6 6. Nd7 Qd4 7. Bxb7 Qxh4
>>>>>>8. Qh2 Qxh2 9. Kxh2
>>>>>> = (1.24)       Depth: 12/48    00:12:16.28     298098kN
>>>>>>
>>>>>>Very tough for Zappa.  5 minutes.  It changes its mind a lot here as well, which
>>>>>>never helps - Rg1, then Rf2, then Rf3, then Rg1, then Rf3 again.
>>>>>>
>>>>>>anthony
>>>>>
>>>>>I wonder how does zappa knows not to consider first Rg1 at depth 12.
>>>>>zappa has a score for Rg1 at depth 11 and the first output at depth 12 is a
>>>>>score for Rf3.
>>>>>
>>>>>Uri
>>>>
>>>>I'm not sure what is strange (other than the slow times): Zappa likes Rg1 at
>>>>depth 11, fails high on Rf3 at depth 12, and ends up with Rf3 as the best move
>>>>at depth 12.
>>>>
>>>>anthony
>>>
>>>The fact that I see no score for Rg1 at depth 12.
>>>Does zappa have a score for Rg1 at depth 12 before finding Rf3?
>>>
>>>If it has a score then I do not see it in the output and if it decides to search
>>>Rf3 before Rg1 at depth 12 then how does it know to do it.
>>>
>>>Uri
>>
>>Zappa only prints the PV at the end of the search - no intermediate pvs.
>>
>>anthony
>
>In this case I have 2 questions:
>1)how can you know the time that it needs to find a move?
>2)why does it print 2 pvs for Rf3 at depth 12 and 2 pvs for Rg1 at depth 7?
>
>Uri

Zappa uses an aspiration window.  The first character shows how the search went:
- -> window failed low, + -> window failed high, = -> good.  So Zappa tried
PVS(p, 0.5) and failed high. Then it tried PVS(p, 1.25) and was successful.  In
other words, Zappa doesn't treat the root position differently.

I'm not sure I'm doing a very good job of explaining this.



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