I was looking at the answer of today's puzzle in chessgames and see that the reason I wasn't able to solve it because I missed a key move in the solution:
note: this is not the puzzle position, this was taken from the middle of the puzzle solution.
note2: the board seems to be correctly flipped.
8/7p/1pBP2pk/pP6/K6P/6P1/1rp5/4R3 b - - 1 49
I don't really see the advantage of doing that move, is it something related to winning tempos? If so, how?