Primary vs. Secondary Fault
The primary fault is the swing issue with the highest severity and impact on performance; the secondary fault is the most likely co-existing issue.
In a complex movement like a golf swing or a tennis groundstroke, multiple faults often coexist. An over-the-top swing path may accompany an open clubface; a late unit turn may produce an arm-only swing and an abbreviated follow-through. These faults do not exist independently — they share a common cause or form a chain where one fault produces another. The primary versus secondary fault framework acknowledges this interconnection and uses it to simplify the training focus: fix the primary fault (the root cause or the highest-impact issue). The secondary fault often resolves partially or completely as a consequence.
The primary fault is selected by the recommendation engine based on severity (how much performance impact it carries) and confidence (how certain the diagnosis is). It is the one issue you are asked to focus on in your current training cycle. The secondary fault is the next highest-ranked issue — present and noted, but not your focus until the primary is addressed and retested. This hierarchy prevents the common coaching failure of assigning multiple simultaneous corrections that compete for attention and produce uneven results.
Understanding the primary-secondary relationship also helps you interpret your results during a retest. If you successfully address the primary fault and the secondary fault improves at the same time without any direct work on it. That is strong evidence that the two faults shared a common cause — the primary fix cascaded into the secondary. If the secondary fault persists after the primary is resolved. It is a genuine independent issue that may become the new primary in your next analysis. Either outcome is informative and moves the diagnosis forward.
Tips by skill level
Focus only on the primary fault during your current training cycle. The secondary fault is visible so you understand the full picture. But working on it at the same time while the primary is unresolved is likely to produce conflicting adjustments and slower progress on both.
If you know the secondary fault costs you more in your current competitive context, discuss it with a coach. For example, it may cost you points in matches while the primary only shows up in practice. The recommendation engine ranks from the data it has, so it cannot weigh match context you have not recorded.
Example
An over-the-top path (primary) and an open face (secondary) often share a cause, so fixing the path frequently squares the face too.
How it shows up on video
The primary fault is shown first in your report, with its priority. Secondary findings follow below it, ranked lower; in Motion Lab's findings list they read Watch at most, while only the main issue can read Fix. The order reflects priority, not an arbitrary sequence.
Common mistakes
- Working on a secondary fault before the primary fault is resolved. Most secondary faults are compensations for the primary fault and will partially resolve once the primary fault is addressed.
- Treating all faults listed in the report as equally urgent — the primary/secondary ordering reflects priority and impact; address them in order.
- Not recognizing that a secondary fault can become primary in a future session — as you work on the primary fault, the secondary fault may become the most impactful remaining issue and surface as primary in the next analysis.
- Completing only primary fault drills while ignoring secondary fault information — understanding secondary faults gives you useful context about how your compensations are structured, even when you are not actively drilling them.
In SwingVantage Motion Lab
Your SwingVantage report shows the primary fault first, with secondary findings listed below it. Motion Lab's Main Issue step also names a likely root cause. That helps you judge whether a secondary finding may ease once you address the primary.
Frequently asked questions
Can there be more than two faults identified?
Yes. The rules engine may identify several fault patterns in a single session, and your report can list them in ranked order. Only the top one becomes your fix; the others are context. Each new analysis ranks what it finds again, so a lower fault can rise once the top issue improves.
What if I think the secondary fault is actually more important than the primary?
The ranking comes from the engine's priority, impact, and confidence reads of your data. You have direct knowledge of your performance that the system does not fully capture. If you believe the secondary fault matters more, record more evidence of its cost, such as launch monitor data showing it in ball flight. More evidence may shift the ranking.
Related terms
- SeveritySeverity is how much a swing fault is expected to cost you in performance. SwingVantage shows it as a priority label, such as High priority, and Motion Lab adds a Fix or Watch status.
- Recommendation EngineThe recommendation engine ranks possible fixes by impact and confidence so you get one high-leverage priority fix — not twenty competing tips.
- Diagnostic ConfidenceDiagnostic confidence is how certain SwingVantage is about a finding. It depends on how much data was available and how reliably the pattern appears.
- Rules EngineThe rules engine is the core that checks your shot data and symptoms against sport-specific target windows to find the best-fitting pattern.
See it in a real analysis
Try SwingVantage on one of your own swings — free to start.