I just finished a blitz game, and this was the final position. I was black.
I actually was forced to resign the game here, because my opponent was a guest and was lagging badly ( He had flagged plus a minute more negative time , and I couldn't abort or adjourn).
I had been planning to meet 1.Qb4 with a nice move, and it's a shame I didn't get to play it.
Here I planned the dynamic 1. ... Ba6!
This being a blitz game, I only really analyzed one move for white-the promoting threat 2.b7. (It's not best.)
White is in a forced mating net! (In 8 !!!)
Stop right here and try to find the mate before you scroll down!
I am (intentionally) inserting a blank diagram to give the solution a little space.
Honestly, I hadn't worked all of this out from here, but I did see a fascinating variation for black (which follows).
2. ... Re2+!
3. ... Qxd1+
Here it looks like black is in a lot of trouble. The queen is under attack, and the threat of b8 is also very strong. Black, however, lands a nice shot.
Next is the last move that I saw in my calculations. I just assumed that black would have at least a draw or at best a beautiful mating combinations. It's a real shame that none of this actually got played.
4. ... Rxf2+!
5.Kxf2 (*5.Kg3 see later)
Here, there are two paths to choose. In my post game analysis, my first choice was 5. ... Qe2+ 6.Kg3 (6.Kg1 Qf1+ 7.Kh2 Qf2 mate) 6. ... Qf3+ 7.Kh4 (7.Kh2 Qf2 mate again).
Unfortunately, here black does not have an immediate mate, but there are some fun variations.
7. ... Qf2+ 8.Kh5 (8.Kg5 Qf6+ 9.Kh5 Qh6 mate) 9. ... g6+
10.Kh6 (not 10.Kg5 h6 mate)
Black is still won, but the mate has slipped away!
The correct response to 5.Kxf2 is much simpler.
5. ...Qf3+ !! is the way to go.
6.Kg1 (6.Ke1 Qe2 mate)
6. ... Qg3 mate
The rook sacrifice (and acceptance) was the fascinating part for me, but there is one more variation to be complete. I didn not even consider ...
Black mates here too, but it takes longer.
5. ... Qf3+
And here 6. ... Qf6+ sets up another pretty variation.
7.g5 (7.Kh5 Qh6 mate) and 7.Kg3 are left.
7. ... Rf4+! ( another superb rook sac ! )
8.Kh5 Be2 mate / 8.exf4 Qxf4+ 9.Kh5 Be2 mate / 8.Kg3
8. ... Qxg5+ 9.Kh2 Rf2 mate
Now, White's other 7th move ...
What analysis would be complete without yet another rook sacrifice ?!!!
7. ... Rg2+!
8. ... Qf3+
9.Kg1 (9.Kh2 Qf2 mate)
9. ... Qg3 mate
It is amazing to me that so many variations can all lead to the same or a very similar final mating position (with just two black pieces!). White's king is really just too loose and completely ripped open after 4. ...Rxf2+!! .
I hope you enjoy this fascinating tactical sequence as much as I did, when I discovered it.