White has an apparently simple capture of a loose piece with RxB. Any problem with this? It's not enough to ask whether the piece you want to take has protection. Ask what tactical possibilities would be available to your opponent after the move. One important clue that you are creating tactical risks is that a capture will leave your piece lined up with another of your pieces—especially your king—since you may be creating the kernel of a pin or skewer. Here the glaring fact about RxB is that it puts White’s rook and king on the same rank. Black can exploit this with Rh2+; White’s king is forced to step aside, and after RxR Black has won the exchange.