Author: Robert Hyatt
Date: 20:04:27 10/11/02
Go up one level in this thread
On October 11, 2002 at 15:39:21, Uri Blass wrote:
>On October 11, 2002 at 14:43:30, Vincent Diepeveen wrote:
>
>>On October 11, 2002 at 13:52:04, Uri Blass wrote:
>>
>>Not really. I just do singular extensions and checks in qsearch
>>when we talk about this position. It would amaze me
>>if deep blue didn't use singular extensions, because even
>>chiptest back in the 80s or something already used it :)
>>
>>>On October 11, 2002 at 13:14:55, Vincent Diepeveen wrote:
>>>
>>>>On October 11, 2002 at 11:03:19, Uri Blass wrote:
>>>>
>>>>DIEP needs 9 ply to see the KRP KRP endgame (so winning
>>>>the pawn on e5).
>>>
>>>You must have a lot of extensions to see it only at 9 plies.
>>>
>>>1...h3 2.Rh6 a3 3.Rh8+ Ke7 4.Rh7+ Ke8 5.Rxh3 Ra4 6.Rh8+ Ke7 7.Rh7+ Ke8
>>>8.Rh1 a2 9.Ra1 Ke7 10.Ke5 Ra5+ 11.Kd4
>>>
>>>If I count only no check moves I get 14 plies even with checks in the qsearch.
>>>
>>>1...h3(1 ply)
>>>2.Rh6(second ply)
>>>2...a3(third ply)
>>>3...Ke7(4th ply)
>>>4...Ke8(5th ply)
>>>5.Rxh3(6th ply)
>>>5...Ra4(7th ply)
>>>6...Ke7(8th ply)
>>>7...Ke8(9th ply)
>>>8.Rh1(10th ply)
>>>8...a2(11th ply)
>>>9.Ra1(12th ply)
>>>9...Ke7(13th ply)
>>>10.Ke5(14th ply)
>>
>>>rest qsearch.
>>
>>let me count for you more clear instead of the
>>above line, of course also extending check escapes:
>>
>>h3 1
>>rxh6 2
>>a3 3
>>rxh3 4
>>ra4 5
>>rh8+ 6
>>ke7 7
>>rh7+ 7
>>kf8 8
>>rh1 8
>>a2 9
>>ra1 10
>>ke7 11
>>NULLMOVE 12
>>qsearch:
>>ra5+
>>something
>>kxe5
>
>In my line I do not have 1...h3 2.Rh6 a3 3.Rxh3 but
>1...h3 2.Rh6 a3 3.Rh8+ Ke7 4.Rh7+ Ke8 5.Rxh3 so it is more plies.
>
>>
>>You see it is trivial that it is 12 ply here without extensions
>>if you do checks in qsearch.
>
>It seems to me 14 plies because Rh8+ Ke7 Rh7+ Ke8 is 2 plies.
>With using hash tables to prune the tree it may be 12 plies without special
>extensions
>
>Uri
I ran this for fun. Crafty on my 700mhz laptop:
11-> 2.79 0.68 1. ... h5 2. Ke5 h3 3. f5 h2 4. Kf6
Kg8 5. Rxh5 Rc2 6. e7 Rc6+ 7. Ke5
Kf7
8. Rh7+
12 8.30 -- 1. ... h5
12 11.92 1.47 1. ... h5 2. Kg5 Rb4 3. f5 Re4 4. Kxh5
Kg8 5. Re7 Re5 6. Kxh4 Rxf5 7.
Ra7
12 19.57 1.13 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Rh1 Ke7
7.
Re1 Ra5+ 8. Kg6
12-> 20.77 1.13 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Rh1 Ke7
7.
Re1 Ra5+ 8. Kg6
13 30.47 0.81 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Kf6 Rxf4+
7.
Ke5 a2 8. Ra7 Rf2 9. Kd6 Rd2+ 10.
Ke5
13-> 37.54 0.81 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Kf6
Rxf4+ 7.
Ke5 a2 8. Ra7 Rf2 9. Kd6 Rd2+
10. Ke5
14 1:15 0.63 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Kf6 Rxf4+
7.
Ke5 Ra4 8. Kd6 Rd4+ 9. Ke5 a2
14-> 1:35 0.63 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Rh8+ Ke7 5. Rh7+ Ke8 6. Kf6
Rxf4+ 7.
Ke5 Ra4 8. Kd6 Rd4+ 9. Ke5 a2
15 3:20 ++ 1. ... h3!!
15 4:38 0.10 1. ... h3 2. Rxh6 a3 3. Rxh3 Ra4 4.
Kf6 Rxf4+ 5. Ke5 Ra4 6. Rh8+ Ke7
7.
Rh7+ Ke8 8. Kf6 Rf4+ 9. Kg6 a2 10.
Ra7 Re4
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