Figure 6.2.11.2[Black to move]

We started in the prior frame with an example on the kingside because that makes it easier to understand the relationship between Boden’s mate and the others we have seen. But Boden’s mate is more common when a player castles on the queenside as shown here. The reason is that after queenside castling the king is left three squares from the side of the board with a rook blocking d8, putting part of the pattern for Boden’s mate already in place. Kingside castling leaves the king two squares from the edge, so it must be moved over for the pattern to work, and then the e-file has to be blocked off. It takes more time and effort—whereas in the pictured position White's bishops are able to achieve checkmate with no help from any other White pieces.