When I'm hitting the ball great, I know my arms and body are matching up well. But sometimes my body takes over at the start of the downswing. That's when I can hit some crooked shots. I want my arms to pull my body, not the other way around, in both directions--swinging back and swinging down.
That's probably different from what you've heard, with all the talk these days about turning the body. The reality is, most golfers have too much body turn and not enough arm swing as they start down. For me, it's my hips that turn too fast. That spins my body open and pushes the club to the outside, so I swing across the ball and hit pulls and fades. For many amateurs, the problem isn't the hips but the shoulders opening too fast. The result is the same: The body races out of sequence, the arms lag behind, and the club cuts across the ball.
To groove your downswing, here are a couple of thoughts: (1) Keep your back to the target for as long as possible, and (2) feel like your chest is facing the ball at impact. These cues will get your arms swinging down in front of you instead of being dragged through by an overactive body. Give them a try, and check out my two downswing drills (below).
Get in your setup, take it to the top (1) and practice swinging the club halfway down and stopping. Repeat this a few times and--here's the key--don't let your hips start unwinding (2). You'll feel your arms come down in front of you. After a while, hit some balls: Swing to the top, pump down twice and on the third time go ahead and rip it. This drill will activate your arms.
Here's a great way to train your body to feel proper impact. Take your address with an iron, and then mimic a good impact position. Push the handle forward, shift your weight to your front foot, get up on the toes of your back foot. Your hips should be open but your chest facing the ball (see video above). Really feel that position, then repeat it when you swing.
Zach Johnson has won seven times on the PGA Tour, including the 2007 Masters.