5/29/2025 DPA

Here's what we have to note about this puzzle:

1. Blacks king is currently stuck on the back rank due to our rook on b7

2. Our rook on b1 is targeted by blacks bishop on g6

3. If the same rook on b1 wasn't on the first rank, black has the possibility to play checkmate with Rd1#

4. We are down 3 points in material, equal to a knight

If we try to check with Rb8#, blacks king will be able to escape off the back rank, and we wont be able to continue our checkmate attack.

We can try to set up mate by playing Rc1, preparing to play Rc8#. But then black is able to force a rook trade by playing Rd1+. And now the position is even.

So, is there any way to keep the king on back rank while also saving our rook on b1? The simplest way to do it is with a check by something other than our rook on b7. We can check with Bc5+, and black only has 2 options. If black plays Kg8, we can play checkmate with Rb8#, so what if black plays the other option, Ke8? We can play Re7+, allowing our rook on b1 to move to b8 when needed, while also giving a check and keeping the king on the back rank. Yet again, black has 2 options (Kd8 and Kf8), this time our other rook can come into play though, and we are able to play checkmate with Rb8# after either of those moves.