In the golf swing, the hips turn and the arms swing. In the backswing, the arms swing back first and the hips follow. In the forward swing, the hips turn first and the arms follow.

When the rhythm and tempo of the swing are correct, each of those movements happen at the right moment and have the chance they need to develop fully.

When that is the case, we say the swing is correctly timed.

Rhythm is the relative duration of the backswing to the forward swing. Tempo is the overall speed of the swing, measured by how long it takes in total.

Rhythm, as explained in part 1 here, is the same for all golfers. Tempo is an individual characteristic, which depends on athleticism, flexibility, and strength.

Good timing is a consequence of proper rhythm and tempo.

What does is mean for the arm and hip movements to develop fully?

For the arms, it means for them to reach a consistent finished backswing position. For the hips, it means turn to the extent that they are slightly open at impact.

The evidence of good timing is clean contact on the center of the clubface. Granted, there is more to that than good timing, but you will get more out of good timing and so-so technique than good technique and a mis-timed swing.

To get good timing, you must give up the idea of hitting the ball as far as you can with the club in your hand, and instead hitting it as accurately as you can with that club.

The key to all this is in large part not rushing the arms at the start of the forward swing. Let the hip turn carry them until the momentum of the turning action releases their swinging action.

And swing through the ball. Don’t try to clobber it at the last moment.