Phony Benoni: Well, I could just refer you to a tablebase like http://www.k4it.de/index.php?topic=.... But let's see I can explain the process. It may help me more than it helps you!
click for larger viewBlack's first step is to advance the pawn to c2. White's bishop will be able to stop this by controlling either the a4-e1 or the a1-h8 diagonal, but he can't hold both. The black bishop will be able to chase it by offering a trade at a time when White will not be able to accept without losing the pawn ending. Black's ideal square for his king right now is b3, so that he can interpose his bishop on either c3 or b2 as necessary. This also keeps the king in a dominant position should the bishops be traded. Here's one possible line: <1.Bf4 Kb3 2.Bg5 Bb4> (Black threatens to advance the pawn, so White's bishop msut take the long diagonal. Black will then bring his bishop to b2 to command the diagonal, and push his pawn.) <3.Bf6 Ba3 4.Be5 Bb2 5.Bf4 c3 6.Be3 c2+>
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White can vary, of course, but Black will always be able to force a position like this. Now, Black brings his king to b1, and plays ...Bc1 chasing White's bishop off the diagonal. It can get back to a3, but then Black moves his bishop around to b2 and White will have no resource. A sample line might be <7.Ke2 Ka2 8.Kd3 Kb1 9.Bf4 Bc1 10.Bd6 Bh6 11.Ba3 Bg7 12.Kd2 Bb2>, and it's all over. This may look tricky, but the winning procedure was first shown in the 18th century and is familiar to any grandmaster. White did not need to be shown. | 
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buttons, but it's much easier to simply use the left and right arrow keys on your keyboard.
