Guide

The 12 golf swing checkpoints, explained

A checkpoint is one measurement taken at one moment of the swing. Twelve of them, read from a single video shot from behind, describe most of what goes wrong in an amateur swing.

What a checkpoint actually is

Coaches talk about swing positions using P-numbers: P1 is address, P2 is when the club shaft is parallel to the ground in the takeaway, P4 is the top, P7 is impact. A checkpoint takes one of those moments and measures one specific thing — an angle, a distance, a displacement from where you started.

The value of measuring rather than eyeballing is consistency. Your eye can tell that a swing looked steep. It cannot tell you that the shaft sat 0.31 outside the reference plane this week against 0.19 last week. Small changes are where practice actually shows up, and they are invisible without a number.

What follows is what each checkpoint measures and why it matters. The specific target ranges below are calibrated for a 7-iron; they shift with the club, because a shorter, higher-lofted club naturally produces a more vertical swing plane than a fairway wood.

Address: the posture that sets up everything downstream

Three measurements at setup, before anything moves.

Too upright and you lose the room your arms need to swing down in front of you. The swing flattens, the club gets stuck behind you, and early extension becomes the only way to make contact. Expect thin strikes, heel strikes, blocks and pulls.

Too bent over and you are reaching for the ball with weight toward your toes. The backswing goes upright, the delivery gets steep, and you catch it out toward the toe.

Too much knee flex is squatting rather than hinging. It limits how far your hips can turn, which forces you to stand up through impact to make space. Too little locks the legs and costs you balance.

Setup faults are worth fixing first because they are static. You can rehearse them in a mirror at home, without a ball, and they change every position that follows.

Takeaway: the first half-metre

One measurement: where the clubhead travels relative to the swing plane in the first part of the backswing.

Too far inside is the common amateur pattern. The wrists roll the face open, the club gets sucked behind the hands, and you now need a reroute at the top to get back to the ball. That reroute is very often an over-the-top move — which is how an inside takeaway ends up producing a slice.

Too far outside pushes the hands away from the body and sends the backswing upright, which delivers the club steeply into the ball. Pulls and slices again, by a different route.

Mid-backswing: shaft plane

Measured when the lead arm is roughly parallel to the ground on the way up. Too steep means you lifted the club with your arms instead of turning your body. Too flat means the club rolled behind you and your hands got deep too early, which usually needs a timing-heavy save on the way down.

Top of the backswing

Hands not deep enough means the arms lifted rather than the body turning. The club ends up steep and the transition tends to start over the top. Hands too deep means over-rotated arms and a flat backswing that needs precise timing to square up — pushes, hooks, and fat shots.

Head drift is the honest way to score loss of posture. A camera behind you sits nearly side-on to your torso at the top, which is exactly where body-tracking models are least reliable at reading shoulder position. The head, on the other hand, tracks cleanly. Any genuine loss of posture moves the head, so measuring the head measures the fault without the noise.

Transition: the checkpoint that matters most

Shaft plane measured at the point where the lead arm is parallel to the ground on the way down. This is the single highest-weighted checkpoint, and a camera behind you is unusually good at reading it.

Over the top or steep: the upper body starts the downswing, the hands and club move out toward the ball, and the club approaches from outside the target line. Pulls, pull-slices, slices, thin contact. The fix is sequencing — let the lower body start the transition and feel the hands fall before the club moves outward.

Too shallow or stuck underneath: the club drops behind the body and the hands get too deep. Now the body has to stall to let the face catch up. Pushes, hooks, blocks and fat shots.

There is a trap worth naming here: a golfer who looks shallow from behind is sometimes just sliding — moving the lower body laterally toward the target instead of rotating. That costs power, because the upper body loses a stable platform to accelerate around, and it looks like a different fault than it is.

Impact

Hip depth measures how far your hip centre has moved toward the ball between address and impact. This is early extension, and it is the second-highest-weighted checkpoint. When the hips push toward the ball your arms lose the space they need to pass through. Heel strikes, shanks, blocks, hooks, topped shots.

Head drift through impact matters because moving your head moves the low point of the swing arc. The club then bottoms out somewhere other than where the ball is, and you get fat or thin contact more or less at random.

Why the checkpoints are weighted differently

Twelve equal scores would be a worse answer than one ranked list. Downswing plane and hip depth carry roughly four to six times the weight of arm hang at address, because they cause far more mishits and because they are the two things a rear-view camera reads most reliably.

That ordering is the entire point. A report that hands you twelve numbers has told you nothing about what to do on Saturday. A report that says this one, and here is the drill has.

What checkpoints cannot tell you

Every checkpoint here is a two-dimensional reading from one camera. That is enough for posture, plane, depth and displacement. It is not enough for clubface angle at speed, where on the face you struck it, or true pressure shift — those need either a second camera or a launch monitor. A useful analysis says which is which rather than pretending the camera saw everything.