What if we have a position like this...a rook pawn with a bishop that could NOT control the destination square?
1.Bd5
Kf8
2.Kf2
Kg7
3.Kg3
Kh8
4.Kf4
Kg7
5.h4
Kh8
6.h5
Kg7
7.Kg5
Kh8
8.h6
Kh7
the only move!
9.Be4+
Kh8
10.Kg6
Kg8
Now, how to get rid of him from the corner?
11.Kf6
Kh8
[If 11...Kf8
12.h7
Ke8
forced! 13.h8Q+
mate follows soon!]
12.Kg5
[If 12.Kf7
stalemate and draw!]
12...Kg8
13.h7+
Kh8
14.Bg6
Kg7
15.Kh5
Kh8
There is no way the Black King can be forced out of the corner! *