Author: Mike Byrne
Date: 16:52:17 08/22/03
Go up one level in this thread
On August 22, 2003 at 17:42:10, Drexel,Michael wrote:
>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
I had taken a second look and you might be right. I will look at it again one
more time.
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