Rule 7 of 25 · Chapter II — The Strike
Make the club reach its lowest point after the ball, not at it or before it.
Why this rule exists
An iron is built to compress the ball against the ground, and that only happens if the clubhead is still descending when it arrives. If the low point sits at or behind the ball, you catch it thin or heavy and lose both height control and distance consistency. Every other rule in this chapter is a way of moving that low point forward.
In practice
On the range, lay a tee or a short line of chalk a couple of inches in front of the ball and try to brush or clip it after contact. On grass, hit shots off a firm lie where you can see the mark — the bruise should sit ahead of where the ball rested. Work in sets of five and count how many low points land in front rather than judging by ball flight alone.
When it doesn't apply
Off a fairway bunker lie, a bare hardpan lie, or a tight winter lie where you cannot risk digging, you may play a shallower, more sweeping strike and accept less compression. Fairway woods and hybrids off the deck also work from a low point at or barely after the ball.