06 Feb '09 00:16>
Originally posted by streetfighterThe only line after a5 that I can find that forces white to take on b4 or a5 is
The idea was to force white to either take on a5 at some point (in which case the e-pawn will queen with check) or for white to have to play b4 when his king is on the b-file (again black would queen with check). In both cases white would have a pawn on the 7th.
However, it may not be possible to force this. I'm going to keep looking - there are often very sneaky ideas hidden in this type of endings : )
1. ...Kxe6
2. Kc6 Kf5
3. Kc5 e5
4. b4 axb
5. Kxb4
but in this position white is able to force black to waste time moving the king to protect the pawn whilst moving his own king to a square from which he will not be checked when black promotes eg
5. ... e4
6. a5 e3
7. Kc3 Kf4
8. Kc2 Kf3
and white promotes in the same move as black without being checked.
Any line where black moves the king anywhere other than the f file after 2. Kc6 results in white playing 3. Kc5, 4. b4 and promoting before black.
If there is a winning line for black I think it must be in maneuvering kings into favourable positions before giving up the exchange and I can't see a way in which this is possible either.