After exchanging bishops somehow, we have to make sure we don’t get forced into a draw by either (a) the Black king getting to a8, or (b) us getting trapped on the a-file by the black king on the c-file. Of our two opening moves, Bb7 and Bc6, the latter leads to one of (a) or (b), since recapturing the B on the fifth rank brings us too far from the black king’s path: 1.Bc6 Ke7 2.Bb5 Bxb5 3.Kxb5 Kd8 and now we can’t stop at least one of (a) or (b).
So that leaves 1.Bb7. This time black cannot exchange B immediately, since our recapturing the B on the 6th rank instead of the 5th rank leaves us close enough to meddle with the black king, setting up a blockade on b7: 1.Bb7 Ke7 2.Ba6 Bxa6 3.Kxa6 Kd7 4.Kb7 and the pawn runs up behind the king.
So black’s only hope in the 1.Bb7 case is if he can use the bishop to stop the pawn from some other diagonal, either (i) the long a8-h1 diagonal, or (ii) the a6-c8 diagonal. We can put an end to that if we can get our king to c7, since that cuts the bishop’s access to c8 and b7, where it could interfere with a6: 1.Bb7 Ke7 2.Ba6 Be4 3.Kc7 and after a6-a7 (after moving our B out the way) we can block the long diagonal (i) with Bb7 and (ii) is prevented by our K at c7.
I know how if it was a f pawn… not sure if I can with h pawn.
How about:
1. Bb7 Ke7
2. Ba6 Bf5 (or 2… Be4 3. Bb5)
3. Bb5 Bc8
4. Kc7
etc.
The “obvious” Bc6 Ke7 Bb5 Bb5 Kb5 Kd7 is a draw. Must be some subtility somewhere ;o)
I agree with Lambent.
After exchanging bishops somehow, we have to make sure we don’t get forced into a draw by either (a) the Black king getting to a8, or (b) us getting trapped on the a-file by the black king on the c-file. Of our two opening moves, Bb7 and Bc6, the latter leads to one of (a) or (b), since recapturing the B on the fifth rank brings us too far from the black king’s path: 1.Bc6 Ke7 2.Bb5 Bxb5 3.Kxb5 Kd8 and now we can’t stop at least one of (a) or (b).
So that leaves 1.Bb7. This time black cannot exchange B immediately, since our recapturing the B on the 6th rank instead of the 5th rank leaves us close enough to meddle with the black king, setting up a blockade on b7: 1.Bb7 Ke7 2.Ba6 Bxa6 3.Kxa6 Kd7 4.Kb7 and the pawn runs up behind the king.
So black’s only hope in the 1.Bb7 case is if he can use the bishop to stop the pawn from some other diagonal, either (i) the long a8-h1 diagonal, or (ii) the a6-c8 diagonal. We can put an end to that if we can get our king to c7, since that cuts the bishop’s access to c8 and b7, where it could interfere with a6: 1.Bb7 Ke7 2.Ba6 Be4 3.Kc7 and after a6-a7 (after moving our B out the way) we can block the long diagonal (i) with Bb7 and (ii) is prevented by our K at c7.
Nice exercise. thanks susan
White pawn will queen :
1.Bc6 Ke7 2.Bb5 Be4 3.a6 Kd6 4.a7 followed by Ba6 and Bb7 1-0
Exchange white bishps.. it is a sure win white.