Force yourself into mate!

This line forces black to mate white quicker.
4. Qe8+ Kg7 5. Bd4+ Bxd4#
@ tonydal
4. Bd4+ does not force black to mate as he can play 4... Kg8
Good point--sorry. You think I'd be better at this sort of thing (the way some of my games go!).
At first I wanted it to be a short puzzle, but the more I analyzed it, the more I realized that a stubborn player behind the black pieces can avoid winning for quite some time! 5.Bd4+ doesn't work, because black can play e5.
Actually, it was another puzzle. I didn't see your puzzle until a couple of days after I posted this one, but when I saw it I felt that my puzzle wasn't as good after all. Your self mate was great!