hey djazbin, man, it's "pinned"; learn your spelling, man.

I overthought this one.  I was thinking maybe start with Qa6 to suck the king out, but it was really simpler than that.

Truly a fine puzzle.

The funny thing is that the only reason black would sack the queen in this instance is if black could see the mate coming.  If black can see the mate coming, then why not anticipate it in some other fashion.  Sacking the queen doesn't even really buy time.

very nice

Deep.

Basic checkmates!

Problem with this puzzle before it starts, black would not have left white's Queen standing.

nice

 fairly straight-forward

very nice

first

awesom 

Great puzzle, especially with the Bishop backing things up from the other end of the board.

very instructive puzzle

That is why you are still an amateur as am I; albeit, a more experienced one whom can easily see the Pin by the White Ice Bishop allowing the Ice Queen to post at a6!

Icee...You see...We should all see the Pin! See!?

First

I was going to say that -- if he doesn't see the pin and mate coming, he just moves Kb7 right away.  But as a practical issue he probably doesn't chuck the queen in there regardless; he resigns or just plays the shorter 4 move mate if he feels like letting his opponent play it out.  The delaying sacrifice only gets played because it's a puzzle and the "mate in X moves" has to include all such time-wasters.

@ slowhare -- previous move ... Rf2 thinking to cause the queen some issues?  Since if QxR it's a back-ranker for the black queen.