The first because he's not a total pussy and the second because he can move. Also, according to Nick Bollettieri, the duo's coach, Big Lar doesn't smile when he's playing, which makes sense considering that while he loves tennis, it ranks third among his favorite things, which are 1) drinking diet Coke and 2) sleeping during work. For those of you who've recently received an invite to knock some balls with Obama's economic team, here's what you can expect:

A quick look at Summers suggests diving for drop shots isn't really his game, though opponents say he's deceptively agile. The typical Summers point will start with a cannon-like serve. If the return is weak, the bulky six-footer will cut the ball off and swing for a difficult angle. Each additional shot is more likely than the last to either be out or un-returnable--the shorter the rally the better. As a player, "Larry is very tenacious ... like his personality," says Bollettieri.

It may come as a surprise that the normally understated Geithner--his trademark verbal tic: "I don't know anything about this, but ..."--would play a similarly incautious game. But, decked out in tennis shorts, Geithner is wont to let it rip. "He's a little different on the court than Tim Geithner the central banker," says one colleague. "When he isn't playing well, it's because he's going for it and missing, not because he's being too careful." Though nearing 50, Geithner is a natural athlete with a runner's physique. He can materialize at net so quickly it feels like he served from mid-court, and the sight of his five-foot-eight-inch frame almost dares an opponent to lob him. This is generally not advisable, as Geithner has more impressive ups than you expect to find at a G-20 summit. One hallmark of a game with the Treasury secretary is an unusual number of overhead smashes. Geithner was, after all, a Summers protégé.

Moneyball [TNR]