Boden's Mate is the two-bishop criss-cross: one bishop checks the king along one diagonal while the other bishop covers the escape squares along the crossing diagonal, with the king's own pieces filling in the rest of its cage. Two long-range pieces, an X drawn across the king, game over.
Its favorite victim is the queenside-castled king: after O-O-O, the king on c8 sits next to its own rook on d8, and if the b-file gets pried open, the criss-cross geometry appears by itself. In real games it's often set up by a queen sacrifice on c6 or a6 to rip that cover away first.
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The bishop on f4 already covers b8 and c7. The other bishop lines up the crossing diagonal.
Draw the X. Deliver the criss-cross mate.
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