Mate With Two Bishops

     This is a two bishop mate that is often recommended(see post #9).

     I just don't understand the logic of the first move.  Can you find these first three moves?

    

According to Nalimov, it's as good as any other move that saves the Bishop. It is attacked, it must move, any safe square leads to mate in 19.

(c1, e1, b4, a5, f4, g5, h6 all mate in 19)

     Rooperi,

My question was why only move one square where the king can attack it, as this
seemed like a wasted move to me, but it looks like there is no better square for
the bishop.

     Thanks.

It probably turns out that attacking the bishop with Kc2 going toward the edge of the board gives back any tempo gained by attacking the bishop.

No better square, yes, but there are equal squares.

The choice of c1 seems to be arbitrary, or maybe it was chosen because it looks odd.

A good puzzle.

rooperi:

My thought process was to lead the King towards the corner and then grab the a1-h8 diagonal while remaining in the middle of the board.  Perhaps that's the thinking behind those first 3 moves?

Oops!  I meant that comment for Zankfrappa.