Big Bertha drivers have been a gold standard, since 1991, for easy-to-hit, ultra-forgiving sticks that mid- and high-handicappers swear by. Big Bertha Diablo looks to spread the love to include highly skilled players, too. The three-piece, all titanium clubhead fuses a light, strong body to a lively clubface and a thin crown (Callaway's thinnest ever at 0.027"). The light frame enables discretionary weight(a 10-gram internal weight chip in the Neutral head; a 15-gram chip in the Draw version) to be welded into the rear. This contributes to a higher moment of inertia (MOI) and a precise center of gravity (CG) placement. "We also use head shape more aggressively than in previous designs to steer the center of gravity to neutral or draw locations," says Dr. Alan Hocknell, VP of Innovation and Advanced Design. In total, the MOI in the Diablo Neutral is 20 percent higher (the Draw version is 10 percent higher) than the Big Bertha 460 driver. Its hyperbolic facethicker in the center, thinner around the periphery works with the more stable head to deliver faster ball speeds on off-center hits (translation: less distance loss) than Callaway's previous titanium drivers.