Five years ago, the two heavyweight contenders among golf-club makers were Callaway, still selling its famed Big Bertha drivers, and its Carlsbad, Calif., neighbor TaylorMade, pioneering moveable-weight technology. Yes, other companies were in the fight, each with its own strengths. Ping made great woods and irons; Cleveland was known for its wedges. Titleist and Mizuno catered to elite amateurs, while Cobra specialized in clubs for the common man. Nike had Tiger Woods. But overall, and especially in the all-important category of drivers, which players replace more often than other clubs and which have the highest price...