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        riddles >> easy >> How Many White Moves Before K-f4? (Chess)
        
(Message started by: ThudanBlunder on Dec 31st, 2007, 3:13pm)
Title: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Dec 31st, 2007, 3:13pm
In the diagram below only the White king makes moves. Black does nothing.
The game ends when White plays K-f4. (At the moment K-f4 is illegal because of the Black pawn on g5.)
How long is the shortest possible game?
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by Aryabhatta on Dec 31st, 2007, 7:18pm
That is a long walk.
[hide]
c1, a1, h8, a8, h1, h7, g5 (I hope...)
[/hide]
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Dec 31st, 2007, 7:55pm

on 12/31/07 at 19:18:40, Aryabhatta wrote:
That is a long walk.
[hide]
c3, a1, h8, a8, h1, h7, g5 (I hope...)
[/hide]

That wasn't a long walk; as c3 is doubly defended, that was an illegal short-cut.
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by cool_joh on Dec 31st, 2007, 8:01pm
I found [hide]38 moves[/hide].

[hide]a2, a1, b2, c1, d1, e1, f2, g3, g4, f5, g6, g7, h8, g8, f8, e8, d8, c8, b8, a8, b7, c6, d5, e5, f5, g4, g3, g2,  h1, h2, h3, g4, h5, h6, h7, g6, g5, f4.[/hide]
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Dec 31st, 2007, 8:41pm

on 12/31/07 at 20:01:41, cool_joh wrote:
I found [hide]38 moves[/hide].

[hide]a2, a1, b2, c1, d1, e1, f2, g3, g4, f5, g6, g7, h8, g8, f8, e8, d8, c8, b8, a8, b7, c6, d5, e5, f5, g4, g3, g2,  h1, h2, h3, g4, h5, h6, h7, g6, g5, f4.[/hide]

Hmm.......a2 doesn't look very friendly either.
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by Aryabhatta on Dec 31st, 2007, 10:24pm

on 12/31/07 at 19:55:52, ThudanBlunder wrote:
That wasn't a long walk; as c3 is doubly defended, that was an illegal short-cut.


Yeah.. I mean c1. Sorry. Edited the post.
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by mikedagr8 on Jan 1st, 2008, 3:39am
I get 56 moves. :-/
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by Hippo on Jan 1st, 2008, 3:41am
Hmm, I am on 70.
[hide](4.a7,17.c1,34.a1,45.h8,52.a8,61.h1,67.h7,69.g5,70.f4)[/hide]

I like especialy Dec. 30. one, but all are nice ;)
http://www.chessbase.com/puzzle/christmas2007/index.htm
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by mikedagr8 on Jan 1st, 2008, 11:43pm
I now get 70 aswell.
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Jan 6th, 2008, 10:39pm

on 01/01/08 at 03:41:58, Hippo wrote:
Hmm, I am on 70.
[hide](4.a7,17.c1,34.a1,45.h8,52.a8,61.h1,67.h7,69.g5,70.f4)[/hide]
I like especialy Dec. 30. one, but all are nice ;)
http://www.chessbase.com/puzzle/christmas2007/index.htm

Hmm...moving only the king, the best I can do is mate in 8:
1) Kf7+  d4
2) Kf6  dxc3
3) Ke6  Kg8 (...Kg7 is mate in 6)
4) Kd7+  Kh8 (...Kg7 is mate in 7)
5) Ke8  Kg7
6) Ke7  Kh8
7) Kf6  c2
8) Kf7 mate.  
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Jan 6th, 2008, 10:58pm
FOR JANUARY 1ST (http://www.chessbase.com/puzzle/christmas2007/chr07-8a.htm)

a) Shortest discovered mate:
1) f3  e5
2) Kf2  h5
3) Kg3  h4+
4) Kg4  d6 mate

b) Shortest perpetual check:
1) f4  e5  
2) Kf2  Qf6
3) Kg3 etc.

c) Shortest reflected mate:
1) d4  d5
2) Qd3  Qd6
3) Qh3  Qh6
4) Qxc8  mate
OR
1) c4  c5
2) Qa4  Qa5
3) Qc6  Qc3
4) Qxc8 mate
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by Hippo on Jan 6th, 2008, 11:04pm

on 01/06/08 at 22:39:14, ThudanBlunder wrote:
Hmm...moving only the king, the best I can do is mate in 8:
1) Kf7+  d4
2) Kf6       dxc3
3) Ke6       Kg8 (...Kg7 is mate in 6)
4) Kd7+  Kh8 (...Kg7 is mate in 7)
5) Ke8      Kg7
6) Ke7      Kh8
7) Kf6     c2
8) Kf7 mate.  


I am not sure with your 7 moves solution. (4) ... KF8. The original one is on the opposition motive. ;)
May be if you change Kd7 Ke8 order ;)

On the other way, I didn't solve the 1.1.2008's (I can look on link provided by you to find solution to first, ..., but I actually didn't solved it)
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Jan 6th, 2008, 11:14pm

on 01/06/08 at 23:04:11, Hippo wrote:
I am not sure with your 7 moves solution. (4) ... KF8. The original one is on the opposition motive. ;)
May be if you change Kd7 Ke8 order ;)

On the other way, I didn't solve the 1.1.2008's (I can look on link provided by you to find solution to first, ..., but I actually didn't solved it)

Yeah, 4...Kf8 and once the Black king gets there, there is no mate.

I can't see one. I have been racking my brains wondering how you got it, but I see you have not found it either.

A few observations:
The Black king must move at least twice. (Why?)
Black cannot be allowed to play Kf8 or Kf6.
Therefore Black cannot be allowed to play Kg7 with the opposition.
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by Hippo on Jan 7th, 2008, 12:31am
I have solved it! :)
[hide]Kf7 Kf8 Ke8 Ke7 Kf6 Kf7/e7/f5[/hide]

Yes your observations are just one step to solution ;)
Title: Re: How Many White Moves Before K-f4? (Chess)
Post by ThudanBlunder on Jan 14th, 2008, 2:53pm

on 01/07/08 at 00:31:01, Hippo wrote:
I have solved it! :)

Dammit, I never considered the opposition-stealing [hide]Ke8[/hide].   :-[  Well done.
I haven't tried the others - no time at the moment.


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