We continue with mating patterns that employ the two bishops. As shown in the diagram on the left (where Black is mated), Boden's mate is similar to Blackburne’s mate but moved and reversed a bit: either way one bishop cuts off the king’s flight squares while the other then stabs at it along a diagonal. And notice that in both mates the king must be prevented from retreating away from the scene of the crossfire. In Blackburne’s mate this function is served by the side of the board because the king is on h8. In Boden’s mate the function is served either by Black’s own pieces or by pieces of yours like White’s rook on e1, which stops the king here from escaping onto the e-file.