How to master the golf checkpoints ?

The easiest way to keep your swing on plane is to have a series of checkpoints. By the way, I'm assuming that you're swinging a driver and that you're right-handed. Here are the checkpoints:

• Checkpoint #1: The first checkpoint is at address. The shaft starts at a 45-degree angle to the ground.
• Checkpoint #2: Now swing the club back until your left arm is horizontal. At that point, the club's butt end (the end of the grip) points directly along the target line. (The target line is the line between the target and the ball. That line also continues forward past the target in a straight line and beyond the ball going in the opposite direction in a straight line. What I'm talking about in this case is one long, straight line.) If the end of the grip is pointing along the target line, you're on plane. If the end of the grip points above the target line, your swing is too flat, or horizontal; if the grip end is below the target line, your swing is too upright, or vertical.
• Checkpoint #3: At the top of your backswing, the club should be parallel with a line drawn along your heels. That's on plane. If the club points to the right of that line, you've crossed the line and will probably hook the shot. A club pointing to the left of that line is said to be laid off. In that case, expect a slice.
• Checkpoint #4: Halfway down, at the point where your left arm is again horizontal, the shaft's butt end should again point at the target line. This position and the one described in the second checkpoint on this list are, in effect, identical in swing-plane terms.
• Checkpoint #5: Impact is the most important point in the golf swing. If the clubface is square when it strikes the ball, what you do anywhere else doesn't really matter. But if you want to be consistent, try to visualize impact as being about the same as your address position, except your hips are aimed more to the left of the target than at the address position, and your weight is shifting to the left side.

To analyze your swing, use a video, a series of still photos, or a mirror — or have someone watch you.
Now remember, this method of mastering your checkpoints is a perfect-world situation. Your size, flexibility, and swing shape will probably produce different results. Don't be alarmed if you don't fit this model perfectly; no more than a dozen players on the PGA Tour do. As with anything else, there's room for deviation.