Idiosyncrasies aside, most great putters share this trait: They address the ball with their forearms forming a straight line with the puttershaft—no kinks, bends or angles. With this arrangement, it's easy to maintain a square putterface through impact and start the ball on the intended line.
Try it, but be careful. Just because you're able to get your forearms and the shaft to line up at address doesn't mean you'll hit pure putts. You also need to maintain the straight-line look from start to finish. Most golfers lose it on the forward-stroke by pulling their left arm toward the target. The result? A push.
Instead, keep your left upper arm tucked against your torso and let your upper body, shoulders and the putterhead smoothly and freely release toward the target. Copy my look in the far photo at right and you just can't miss.
Kevin Weeks is the Director of Instruction at Cog Hill Golf & Country Club in Lemont, Ill.