Shot patterns
Dispersion and Shot Selection: Compare the Pattern You Actually Collected
An average describes the centre of a sample. Dispersion describes its spread. Neither is meaningful without knowing which shots were included.
By FORJ
Source-backed educational guide. Fitting suggestions are editorial guidance, not FORJ test results or an expert-approved fitting protocol.
Two combinations can produce the same average carry and very different shot patterns.
A fitting comparison should show both.
The average can hide the difference
Arithmetic illustration—not evidence from a fitting
| Sample | Five carry distances | Average | Shortest-to-longest range |
|---|---|---|---|
| A | 148, 149, 150, 151, 152 yd | 150 yd | 4 yd |
| B | 130, 140, 150, 160, 170 yd | 150 yd | 40 yd |
If needed, scroll this table horizontally. Keyboard users can focus the table region and use the arrow keys.
The averages match. The observed carry spreads do not.
This example demonstrates arithmetic only. Five invented shots establish no minimum sample requirement and prove nothing about equipment performance.
The same issue applies laterally. A tightly grouped pattern can still sit away from the intended target. Consistency and accuracy are different questions: how concentrated are the shots, and where is that concentration relative to the target?
Define the dispersion measure
“Ten yards of dispersion” is incomplete.
Does it mean:
- Carry standard deviation?
- Left-to-right width?
- Shortest-to-longest carry range?
- A region enclosing a stated proportion of shots?
- Carry positions or final resting positions?
Trackman identifies its consistency measure as standard deviation for the parameter being examined. Carry standard deviation describes carry variation; it does not, by itself, describe the complete two-dimensional shot pattern.
Nor is standard deviation a confidence interval for the average.
Selection changes the result
Trackman’s documentation states that selected shots determine the displayed average. The same principle applies to any comparison: changing the sample changes the summary.
Our recommended editorial approach is to distinguish:
- Confirmed measurement failures.
- Deliberately different shot types.
- Valid shots relevant to the player’s normal game.
A valid miss should not disappear simply because it makes a candidate look worse. Conversely, a confirmed tracking failure should not be treated as a genuine performance result.
Record exclusions and their reasons. Do not rely on an automatic “bad shot” threshold or delete shots after seeing which combination benefits.
Compare fairly before declaring a winner
Use a common target and coordinate scale. Keep the ball and settings consistent where practical. Record sample sizes, test order, and meaningful changes in player condition.
If excluding one shot reverses the recommendation, show that sensitivity and collect more evidence rather than presenting a decisive winner.
A fitting result should explain the misses—not make them disappear.
Sources & editorial note
Source-backed educational guide. Fitting suggestions are editorial guidance, not FORJ test results or an expert-approved fitting protocol. Numerical illustrations are labelled where they appear; reference-chart values are not results from a FORJ fitting. Links identify the original publishers and do not imply their endorsement.
Shot-selection recommendations above are editorial guidance, not a statistically validated FORJ protocol.