Driver Impact Location: Check the Face Before Explaining the Flight

A spin number tells you what happened to the ball. It does not tell you which part of the collision produced it.

Before reaching for a lower-spin shaft or changing loft, complete the picture: where was contact, and was that contact representative of the player’s pattern?

The face is not one uniform surface

Drivers have roll, the face’s vertical curvature, and bulge, its horizontal curvature. The face orientation at the contact point can therefore differ from its orientation at the geometric centre.

Trackman’s club-data definitions account for this: its reported dynamic loft and face angle refer to the face orientation at the impact location.

That distinction matters. A different dynamic-loft reading does not necessarily mean the golfer changed their hand position. Contact at a different height on a curved driver face is another consideration.

Strike location also affects spin

Face orientation is only part of the story. Off-centre impact can rotate the head during the collision, producing gear effect that influences the ball’s spin.

Trackman identifies vertical gear effect as an important influence on driver spin. Its spin-rate guidance specifically recommends considering the contact point when interpreting the number.

These effects operate together. The resulting flight reflects the combination of delivery, impact location, clubhead properties, and ball—not a single isolated parameter.

This is why “high spin means the shaft is wrong” is an incomplete diagnosis. A shaft change may alter the result, but the spin reading alone cannot establish the mechanism.

Compare patterns, not just averages

Consider an illustrative comparison—not a FORJ session:

• Build A produces predominantly low-face contact.
• Build B produces contact nearer the centre.
• Build B also produces different launch and spin.

That is a useful fitting observation. But it does not isolate the shaft’s mechanical contribution, even if the shaft was the equipment variable changed. The player’s delivery and strike response may have changed too.

Do not remove that response from the evaluation. A build that helps the player produce a more useful strike pattern may be valuable. Simply describe the observed outcome without claiming to have proved its cause.

What to record

Our recommended comparison includes:

• Impact height and heel-to-toe location, where available.
• Ball speed, launch, spin, and shot direction.
• Relevant delivery measurements.
• The spread of contact locations—not only their average.
• How impact location was established.

Smash factor can prompt investigation, but it is not a substitute for observing strike location.

The next test

Before explaining a launch or spin change, compare the strike patterns. Then test whether the candidate improves the player’s useful flight and dispersion across representative shots.

If the strike evidence is missing, say so. The correct next step may be another measurement rather than another component.

Check where the ball met the face before deciding why the flight changed.

Sources & editorial note

• Trackman: Club Data Definitions
• Trackman: Spin Rate
• Trackman: Smash Factor

Source-backed educational guide. Fitting suggestions are editorial guidance, not FORJ test results or an expert-approved fitting protocol. Links identify the original publishers and do not imply their endorsement.