2009 GOLF Buyer's Guide: Drivers

Callaway Big Bertha Diablo
$299, graphite; callawaygolf.com

It's for: All skill levels

Dr. Alan Hocknell, VP of Innovation and Advanced Design: "Previous Big Bertha drivers target golfers who need the most help with their game. Big Bertha Diablo differs because its performance is optimized for a broad range of golfers, including those of the highest ability. Its new body shape is functional and dynamic."

How it works: Big Bertha Diablo is built for speed and distance. The all-titanium head fuses a lightweight body, a lively clubface and a thin crown (Callaway's thinnest ever at 0.027"). Using a light frame allows discretionary weight (a 10-gram internal weight chip in the Neutral head and a 15-gram chip in the Draw version) to be welded into the rear for a higher moment of inertia (MOI). The
head shape steers the center of gravity (CG) to 'neutral' or 'draw' locations (Unconventional shapes generally require less discretionary weight to increase MOI and lower CG.) The MOI in Diablo Neutral is 20 percent higher (the Draw version is 10 percent higher) than Big Bertha 460. A hyperbolic face combines with the ultra-stable head to generate faster ball speeds on offcenter hits (resulting in less distance loss) than previous titanium drivers.