Arc Consistency

Arc consistency in simplified terms, displays how stable your swing radius (effective arc) stays as you fire into the ball. When the radius stays relatively constant, the ratio-like signal is steady. When the arms shorten or widen abruptly — chicken wing, early release, standing up, or fatigue collapse — the signature becomes more variable or collapsing.

This metric requires precise sensors data. On older watches or basic models with slow sensors the metric may show N/A. When in doubt, trust video and ball flight alongside the number.

How it’s classified

The available statuses are:

  • CONSISTENT
  • VARIABLE
  • COLLAPSING
  • N/A

CONSISTENT

CONSISTENT

Stable relationship during the downswing — effective arc and radius stay coherent swing to swing.

Green (good): Your downswing “arc math” lines up — everyhting looks steady.

What it means

The signal suggests the swing arc does not wander wildly through the downswing: the club is moving on a repeatable spatial path. Paired with solid contact, this is what most players want from width, structure, and connection.

Why it’s a problem

Not a problem. Losing consistency here usually precedes visible two-way misses or distance drop when the hands rescue a changing radius.

Common causes

  • Routine breakdown under pressure.
  • Club too heavy for fatigue level late in a long session.

How to fix

  • Baseline maintenance — same posture, same grip, same width feel at address.
  • Stop when arc traces drift late in the bucket — see COLLAPSING.

VARIABLE

VARIABLE

Changing effective radius during the downswing — arms bending, pulling in, or losing width.

Yellow (moderate / warning): The arc is not holding — often connection, chicken wing, or early extension.

What it means

Your swing arc fluctuates through the downswing: sometimes the hands pull in, sometimes the body stands, sometimes the trail elbow folds early (chicken wing pattern). You can still hit good shots, but timing usually has to save you.

Why it’s a problem

Variable arc consistency tends to produce:

  • Two-way misses — thin/heel when you pull in; block/hook when you throw to save.
  • Distance inconsistency — effective lever length changes swing to swing.
  • Wedge yips risk long-term if micro-radius changes dominate short shots.

Common causes

  • Chicken wing — trail elbow bending and pulling the handle up and in through impact.
  • Early extension — hips thrust toward the ball; arms have to shorten to reach impact.
  • Over-the-top path corrections — hands re-radius to avoid a slice start line.
  • Grip tension — kills width and encourages pulling instead of swinging.

How to fix

  • Extension drill — lead arm feels long through impact; palm to target in slow motion without cupping aggressively (coach the details for your pattern).
  • Gate drill — two headcovers or bottles outside the ball line on the range; swing without touching them to encourage width on plane.
  • Trail pocket visibility — classic cue: keep trail shoulder working under instead of arm folding immediately post-impact (film from face-on).
  • Smoothness and transition — often VARIABLE arc pairs with MODERATE/JERKY smoothness; fix tension and transition first.

COLLAPSING

COLLAPSING

Strong signature of shrinking radius — fatigue, bailout, or structural breakdown in the downswing.

Red (bad / critical): The effective swing radius is shrinking through the hit — power and control leak together.

What it means

The signal points to arc collapse: the swing radius shrinks materially during the downswing or through impact. This is more severe than ordinary variability — think standing up and pulling in, massive early release with short arms, or physical exhaustion making you cannot hold structure. This status also triggers when the app detects your arc proxy has dropped below 80% of your session average, which is a reliable fatigue signal even when the within-swing CV is moderate.

Why it’s a problem

Collapsing radius usually delivers:

  • Heavy power loss — you shorten the lever at the worst time.
  • Thin and weak flights when the low point shifts.
  • Compensatory flip — hands add loft and hook to save contact.

Common causes

  • Fatigue — end of long range sessions, too many drivers in a row, dehydration.
  • Overswinging — loss of balance forces pull-in recovery.
  • Injury or limitation — cannot rotate or extend without pain; body shortens the arc protectively.
  • Steep or stuck patterns that require a pull-in to find the ball.

How to fix

  • Take a break — if COLLAPSING appears late in a session only, it is often fatigue. Rest, hydrate, shorten session, or drop to smooth 8-iron swings.
  • Smaller bucket, higher quality — fewer balls with full commitment beats grinding with a shrinking arc.
  • Extension and gate drills — same as VARIABLE but emphasize slow-motion structure before speed.
  • Professional assessment — if collapse appears fresh every session early, get video and possibly medical screening; do not force width through pain.

Sensor requirement and N/A

Arc consistency is meaningful only when sensor data is trustworthy. The metric shows N/A when: sensor data is unavailable, the downswing is extremely fast overpowering the sensor. Also, wrist position, and how you wear the watch can all affect stability. Use this metric as one trend line in a multi-metric dashboard — not a single-word verdict on your swing.

Quick pairing guide

Watch pattern Often check
VARIABLE + EARLY RELEASE (wrist) Casting and loss of width
COLLAPSING + ABRUPT follow-through Fatigue or fear braking
CONSISTENT + poor ball flight Aim, face, path — arc is not the primary leak