It is usually a bad idea to have doubled and isolated pawns. However, all chess rules have exceptions. Doubled pawn can give you open files for your rooks to attack on. Isolated pawns can give open diagonals for your bishops to attack on.
If you have pawn weaknesses, you can sometimes compensate for them by having active pieces.
In this week’s problem, Black’s pawn structure is a wreck. But he has left himself with just the right pieces to exploit the open lines in this position. He has the two bishops and two open files for his rooks to attack on.
Black can’t play Rxb2, because his rook becomes trapped after Bb3.
What is the best move for Black? This is a difficult problem. One clue is that Black would like to have a bishop on e5. That means moving the f-pawn, which means that the bishop on f5 is on the wrong square at present.
The solution to last Monday’s problem is that White plays 1. Bb5 d4 2. Ba4 d3 3. Bxc2 dxc2 and White draws through stalemate.