This is one of the quirky questions the hyper-productive blogger and cultural economist Tyler Cowen posed to Peter Thiel recently. Here is Thiel’s reply (the aside in brackets was added by us):
THIEL: It’s probably the case that D4 is marginally better at this point, because it looks like there are certain defenses to E4 that are very hard to break, like the Berlin defense. But I still always play E4. It’s what I’ve gotten used to.
COWEN: Because it’s the attacking move, right?
THIEL: It’s the attacking move, and if you’re short of world champion level [i.e. if you have nothing to lose!], I always enjoy increasing the risk involved and volatility in the game.