From Sunday's final of the Madrid Open:
The greatness of Nadal's Tweener is in its genuine improvisation. Nobody plans to hit the shot; they're all inherently hit off the cuff. But look at Federer as he goes back to hit his defining Tweener in the 2009 U.S. Open (also against Djokovic, coincidentally). Federer knows he's going to hit the shot the instant he starts back on the ball. He's setting up his angle, his approach and his swing the entire time.
Now watch Nadal again. There's a moment where he thinks he can go over the shoulder with it. He decides against that, pulls back and then, and only then, opts for the Tweener. Throw in the fact that he pulled it off after a 19-shot rally and during a crucial break opportunity after dropping the first set and it becomes even more special.
We'll conveniently forget about the fact that Nadal went on to lose to Djokovic, snapping his 37-match clay court winning streak.
Follow Yahoo! Sports on Facebook and be the first to know about the most interesting stories of the day.