White, up two pawns and the exchange, blunders - but the mating threat is not obvious and took me (as black) a couple of hours to sort out. Check out the diagram below and see if you can "solve" it. Black can, at worst, trade a Rook for the Queen. At best Black wins the White Queen outright or simply gets mate.
While the first move for Black is obvious, later moves are tricky. White can escape in several ways. One common theme is trading Queens by blocking a check with Qf2 or Qf3. White can also escape along the 8th rank or by "rounding" the cape: the King goes around the d3 pawn and finds safety in the shelter of the pawns when Black can no longer keep putting him in check.
See if you can plot the right moves for a Black victory!
At first glance, the threat doesn't appear horrible. Sure, the King will be placed in check, but surely the dominant placement of the Queen in the middle supported by the Rook will break up any assault, right?
The end of the game makes me laugh. White's Queen and Rook and have tickets to the ballet. They're not just in the front row. They're on stage. With the dancers. The mating dance swirls around them and they stand still like spectators, unable to join the action.
I was fortunate that I was reading two Dan Heisman Novice Nook articles right before looking at this game. First was It's Not Really Winning a Tempo. Second was Three Types of Reasonable Threats. Both articles discuss impotent threats that beginner's often make, threats that do more harm to the threatener than the opponent. I realized I had been guilty myself earlier this game.
I fought on but had given up hope of a swindle, retreated, and then BOOM. He plays 27. Qf5+?? Sure, it puts Black in check, but adds no real danger. Black's next move is forced, and then the 15 point blunder. White manages to go from up more than a piece to down more than a queen. With one move.
Thanks, Novice Nook!
Here's the whole game, if you'd like to see how it played out.