White’s goal remains getting a heavy piece—now it will have to be a rook—onto h8. Rh3 doesn’t work; before White can follow up with Rh8, Black has a chance to play Rxf6 and create a flight square for his king on f7. The problem is that White is behind a tempo. In the positions like this we saw earlier in skeletal form, the king generally starts on the h-file; then when White plays a move like Rh3 he checks Black’s king, the king moves to g8, and Rh8# follows. Here Black’s king is ahead of the game, already on g8 where it can't be checked. What to do? The solution is to make a sacrifice to drag the king back to the h-file. Anderssen thus played Bh7+ and Black was forced to reply KxB. Now we have the needed pattern: White can play his rook to h3 with check, Black moves his king to g8 with no time to create a flight square by moving his rook, and White finishes with Rh8#.
This is another of the most celebrated combinations ever played. It illustrates again the scale of the imagination and sacrifice that may be required to achieve mate. It more particularly is another study in the dogged creation of the mate on h8 that we associate with Anderssen. Notice again how in the final position Black’s queen was taken out of the action, leaving Black with no pieces defending the sensitive squares near the king. (A knight in the vicinity would have come in handy.) White’s bishop check toward the end also is a frequently useful idea: the sacrifice of a piece to decoy the king out onto a file where it can then be checked by another piece until it finally is mated.
Adolf Anderssen, the player of the White pieces, was a German chessplayer of the 19th century, and was considered for a number of years to be the best in the world. He also was the winner of two other games that are among the most famous ever played—his “Immortal Game” against Kieseritzky (1851) and the “Evergreen Game” against Dufresne (1852). Both contain sparkling combinations and mates; if you enjoy playing over old games, you can find those two in any number of anthologies.