Lose - Think ouside the box

I think I have one in five.

1. Kf1 a7xb6 2. Ke3 0-0 3. Qg1 Rb8 4. Qf2 Ra8 5. g4 Qxf4#

Declare me your master.

FORCE defeat... Don't just find A defeat

woodencardboard, Ke3 wasn't legal in your line. It's still not if 1. Kf2, the black knight attacks e3.

Are white's moves supposed to be forcing? Black will be forced to checkmate white?

Heck, I was just impressed that somebody spelled the word "lose" (meaning "to not win") rather than "loose" (meaning "not tight"). A person from Portugal has better spelling ability than many Americans posting on this site...

Just a humorous note that has absolutely nothing to do with the topic at hand....

Is this a puzzle?  Because I don't see any board on this page... What's the starting position?

There is a board... But anyway, here's the string

r1b1k2r/p1pp1p1p/1B3p2/4pnq1/1bBnPP2/2N2NP1/PPPP3P/R2QK2R w KQkq - 0 1

Thanks - very odd, but I can't see the board here, it's the only puzzle where I've ever run across that.

I wonder how you can force anyone to checkmate you. You can close in your own king, and lure the enemy king to some place but with this many pieces it looks impossible. Black can always do something like Rf8 Rh8 Rf8 Rh8 etc. So white should at least get rid of inactive pieces, which are too many. Getting white's king near is impossible and takes too many moves.
I wonder if there is a way at all.