WIN-J · GOLF NOTEBOOK
Golf shot dispersion analyser
Plot measured forward distances and lateral offsets. Review the mean point, target errors, sample standard deviations and the observed 80% radius, then save your shots as CSV and the chart as SVG.
Analysis results
The horizontal axis is lateral offset; the vertical axis is forward distance. Both axes use the same distance scale, with the target and observed mean marked.
Shot records · forward distance, lateral offset per line
| Shot | Forward distance | Lateral offset | Target error |
|---|
How to use
- Name the club or session and choose carry or total distance. Keep one distance basis throughout the analysis.
- Select metres or yards and enter the target forward distance.
- Enter forward distance and lateral offset for each shot on its own line. Left is negative, right is positive, and the target has zero lateral offset.
- Calculate and compare the observed mean point with the target, plus the forward and lateral sample standard deviations.
- Review the observed 80% radius alongside individual target errors and download CSV or SVG. No shots are removed automatically.
Worked example
For a 150 m target and shots 148,-4 / 152,4 / 150,0, the mean point is 150 m forward with zero lateral offset. Target errors are about 4.47 m, 4.47 m and 0 m; RMS error is about 3.65 m. Lateral sample standard deviation is 4 m.
Methods and limits
Coordinates are forward distance from the tee and lateral offset from the target line. The target is at (lateral 0, forward target distance); do not confuse straight-line distance with forward distance. Conversion uses exactly 1 yd = 0.9144 m. Sample standard deviations use n−1 and are undefined for one shot. For the observed 80% radius, sort distances from the observed mean point and select rank ceil(0.8×shot count). This is not a future success probability or confidence region. All shots are included; GPS, ball flight, weather, spin and equipment accuracy are not estimated. Limits: 200 shots, forward/target distance above 0 and at most 1000 m, lateral offsets within ±500 m, and text up to 100 KiB.
Frequently asked questions
What do left, right and forward distance mean?
Use negative lateral values left of the target line and positive values right of it. Forward distance is the component along the target line. A device’s horizontal straight-line distance may have a different meaning, so check what your device reports.
Can I mix carry, total distance, metres and yards?
Use the selected unit and one carry/total basis for every shot in an analysis. Mixing carry with total distance including roll makes comparisons unclear. Prefer the same club and comparable measuring conditions too.
Does the 80% radius predict my next shot with 80% probability?
No. It is a nearest-rank radius containing at least 80% of the entered observations around their mean point. It is not a forecast, future success rate or confidence ellipse.
Can I enter just one shot or a large miss?
One shot still shows its point and target error, but sample standard deviations are undefined. Large misses are not automatically excluded. Do not treat a small or selectively entered sample as your overall ability.
What do CSV and SVG exports contain?
CSV stores the entered shots and their calculated target errors; SVG saves the current dispersion chart. Files are created on your device. This tool does not connect to launch monitors or course accounts or collect measurements automatically.