Author: Drexel,Michael
Date: 14:42:10 08/22/03
Go up one level in this thread
On August 22, 2003 at 16:58:42, Mike Byrne wrote:
>On August 22, 2003 at 15:55:42, Drexel,Michael wrote:
>
>>On August 22, 2003 at 15:52:37, Drexel,Michael wrote:
>>
>>>On August 22, 2003 at 14:59:13, Mike Byrne wrote:
>>>
>>>>On August 22, 2003 at 14:50:09, Mike Byrne wrote:
>>>>
>>>>>On August 22, 2003 at 14:39:35, José de Jesús García Ruvalcaba wrote:
>>>>>
>>>>>>On August 22, 2003 at 09:55:42, Mike Byrne wrote:
>>>>>>
>>>>>>>On August 22, 2003 at 09:42:38, Alastair Scott wrote:
>>>>>>>
>>>>>>>>[D]8/p2k2p1/1p6/5P1p/P5P1/5K1P/8/8 w - - 0 48
>>>>>>>>
>>>>>>>>How long does your engine take to see that gxh5 loses?
>>>>>>>>
>>>>>>>>(A surprisingly long time in some cases - for example, 12 seconds for Ruffian
>>>>>>>>1.0.1, Athlon XP 2600+, 512MB RAM, 32MB hash).
>>>>>>>>
>>>>>>>>Alastair
>>>>>>>
>>>>>>>show me the win after gh5 , I can't find it ....and neither can crafty or
>>>>>>>shredder
>>>>>>
>>>>>>It is very easy, black puts his king of f6, then creates a passed pawn with a6
>>>>>>and b5, and the captures all white pawns on the kingside. The only thing white
>>>>>>can try is to left black with an h-pawn, but that still loses. A posible
>>>>>>variation
>>>>>>1. gxh5? Ke7 2. h4 Kf6 3. Ke4 a6 4. h6 gxh6 5. h5 b5 6. axb5 axb5 7. Kd5 Kxf5 8.
>>>>>>Kc5 Kg5 9. Kxb5 Kg4 10. Kc4 Ke3 and black wins
>>>>>>White can also try leaving the pawn in h3 or h4, or moving the king first to f4
>>>>>>instead of e4, but after 1. gxh5? black wins.
>>>>>>José.
>>>>>
>>>>>nice try,but it doesn't work
>>>>>
>>>>>
>>>>>1. gxh5? Ke7 2. Ke4! {h4? does lose} Kf6 3. Kd5 ! and after the pawns on the
>>>>>Q-side cpme off, it is a draw - Black cannot force a win on the K-side.
>>>>
>>>>for example after 3. Kd5 Kxf5? 4.Kc6! wins for white - so black must play 3.
>>>>...a6! any other move loses for black ...4.Kc6 ensures no outside passer
>>>>survives and resulting position is a dead draw.
>>>>
>>>>[d] 8/6p1/5k2/1K3P1P/8/7P/8/8 b - - 0 6
>>>>
>>>>this is a book draw, if black plays Kxf5 - the simplest way to draw is h6!.
>>>
>>>Very good explanation.
>>>
>>
>>[D] 8/4k1p1/pp6/5P1p/P5P1/5K1P/8/8 w - - 0 1
>>
>>>
>>>This position requires even more skills.
>>>Can white play 1.gxh5 and still draw this position?
>
>I don't think so- a winning theme here to bring the Black King back to g8,
>forcing white to play h6, because once the Black King comes up the h file, it's
>all over. First after gh5, black plays b5, then white's a5 is forced - any
>otehr move loses easily - this manuever effectively limits how far the white
>king can roam
>
>black, with proper use of zugzwang , will win this position IMO
Looks like black is winning after a5 since he has a protected passed pawn but
according to my analysis it is still a draw.
[Event "?"]
[Site ""]
[Date "2003.08.22"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[Annotator "Drexel,Michael"]
[SetUp "1"]
[FEN "8/4k1p1/pp6/5P1p/P5P1/5K1P/8/8 w - - 0 1"]
[PlyCount "17"]
1. gxh5 b5 (1... Kf8 2. Ke4 Kf7 3. Kd5 $11) (1... Kf7 2. Ke4 b5 3. axb5 axb5 4.
Kd5 $11) (1... Ke8 2. Ke4 Ke7 3. Kd5 $11) (1... Kf6 2. Kf4 b5 3. a5 $1 Kf7 (
3... Ke7 4. h4 Kf6 5. Ke4 Kf7 (5... b4 6. Kd4 Kxf5 7. Kc4 Kg4 8. Kxb4 $11) (
5... Ke7 6. Kd4 Kf8 7. h6 gxh6 8. h5 $11) 6. Kf4 Kg8 7. h6 $1 gxh6 8. h5 $11 (
8. f6 $11)) 4. h4 Kg8 (4... Kf6 5. Ke4 $11) (4... b4 5. Ke3 $11) 5. h6 gxh6 6.
h5 Kf7 7. Ke3 $11) 2. a5 $1 (2. axb5 $2 axb5 $19) 2... Kf6 3. Kf4 Kf7 4. h4 Kf6
(4... Ke7 5. Ke5 Kf8 6. h6 gxh6 7. h5 Ke7 8. Kd5 Kf6 9. Ke4 b4 10. Kd3 Kg5 (
10... Kxf5 11. Kc4 Kg4 12. Kxb4 Kxh5 13. Kc5 Kg4 14. Kb6 h5 15. Kxa6 h4 16. Kb7
h3 17. a6 h2 18. Kb8 h1=Q 19. a7 $11) 11. f6 $1 Kxf6 12. Kc4 $11) (4... Kg8 5.
h6 $1 $11) 5. Ke4 Kf7 6. Kf4 Kg8 7. h6 $1 gxh6 8. h5 (8. f6 $11) 8... Kf7 9.
Ke3 $11 *
Michael
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