An endgame exercise

White on move

These days I am in a very good mood for bishop endgames.
That is why I decided to share with readers some more analyses which I made from simple positions from endgame books.
This is one of my favourite examples. Not so long time ago I published analyses of a very similar bishop endgame under the title Problem solving techniques .
This time I played a little with the position and I switched everything for one line  right.
A question is can white win this position.
I shall publish a solution in one of my next posts, but I need to give reader some hints about position.

Obliviously there is no wins with bishop on d7 because black king is placed very good.
It is not possible to win with same technique like in Problem solving techniques article, 
because short diagonal has a two squares b7 and a6, so is it possible to do something to win this position?

White on move

This position is nothing but a version of previous position.
I improved (or not ?) a bit the position of white king, because now white can control one square on the short diagonal (b7) with his king, and he anyway doesn´t need his king on d8 because  a manoeuvre with bishop on d7 is not possible.
Is it possible to win this position?
Think about that black bishop is restricted to occupy a6 square on the short diagonal.
This two examples are quite easy but are essential for more complicated cases.
The next example is a border case for positions with bishop (c, f) pawn.

White on move

This is a final version of this example with c (f) pawn.
White king has improved position but a black king is also better placed on b6.
A move Bb7 is not possible anymore for white in a moment when black bishop comes to a6.
A real exercise is to draw a right conclusion about this three positions.
A fourth example is with a white king on d8 and a black king on b6, but that is not worth to analyse because white just wins with a transfer of his bishop to d7.
If black bishop already occupies short diagonal, than the solution can be to push it on long diagonal with Bc8 and then to try to win with Bd7. Is this possible?

White on move

The last example is a bit more complicated (but nothing special), because white pawn needs to step on two squares which can be controlled by black bishop.
Secondly, white has an enemy of all winning tries in the many endgames, pawn on the rook line.
But here, that means there is not two diagonals for black bishop.
As a good news here, black controls g5 square.
Can white win this position?
What happens if black has king on e6 instead of g4 ?
In both cases white is on move.
Solutions will be published soon.