Methodology
True Strokes Gained requires shot-level start/end context (e.g., putt starting distances). This MVP is a proxy model that uses aggregate round statistics to estimate where you gain and lose strokes relative to your handicap peers.
SG Category Formulas
| Category | Formula | Weight |
|---|---|---|
| Off the Tee | (FIR% - peerFIR%) x 6.0 + (peerPenalties - penalties) x 0.8 | 6.0, 0.8 |
| Approach | (GIR/18 - peerGIR%) x 8.0 | 8.0 |
| Around the Green | (scrambleRate - peerScramble%) x 5.0 | 5.0 |
| Putting | (peerPutts/18 - playerPutts/18) x 4.0 + clamp(threePuttBonus, -0.5, 0.5) | 4.0 |
Data Sources & Citations
Assumptions & Limitations
- Proxy model — not true SG Putting (requires putt starting distances)
- Composite averages — weighted composites from public reports, not a single sampled dataset
- Provisional — sample sizes per bracket not yet available
- Weights — heuristic starting values (6.0, 8.0, 5.0, 4.0), subject to calibration
Calibration Sanity Check
Weights are heuristic, pending calibration against a validation dataset. The table below shows computed SG totals for representative fixture rounds to verify directional correctness.
| Scenario | HCP | Score | Expected Direction | Actual SG Total |
|---|---|---|---|---|
| Scratch good round | 2 | 73 | Positive (better than peers) | +1.21 |
| 10-HCP average | 10 | 82 | ~0 (near peer average) | +0.27 |
| 15-HCP bad round | 15 | 98 | Negative (worse than peers) | -5.26 |
| 20-HCP typical | 22 | 97 | ~0 (near peer average) | -1.28 |
| 30+ HCP round | 35 | 110 | Negative (worse than peers) | -2.00 |
Changelog
- v0.2.0 (2026-03-01) — Shot Scope data for core metrics (brackets 0-5 through 25-30). Average score derived from par-hole averages. FIR% confirmed non-monotonic across handicaps.
- v0.1.0 (2026-02-28) — Initial seed data. Provisional.