Increasing your clubhead speed is a great way to hit the ball further on the course, but how can you find those extra yards?

You don’t have to look far for a power tip. Players have always been obsessed with hitting the ball longer—whether you’re a club player, competitive junior, Tour pro or World Long Drive competitor.

Lee Trevino, in a sweet slow-motion video, rockets a tee shot down a fairway. He laughs. “Now there’s a perfect backswing,” he says. Indeed. There’s a bigger point here, though. Moments earlier, the ...