What does launch monitor club data mean, and which units measure it?

Ball numbers tell you what happened. Club numbers tell you why.

Ball data describes the shot: how fast, how high, how much spin. Club data describes the swing that caused it. If you want to practise rather than just play, it's the club numbers that tell you what to change. They are also where launch monitors differ most. Some measure seven club numbers, some four, some none, and several need stickers, a marker or a paid upgrade before they show anything.

The definitions below come from Foresight's guide to ball and club data and Uneekor's club sticker guide. The other makers use the same meanings, sometimes under different names.

The club numbers, one by one

Club speed

How fast the club head is moving, in mph. Foresight measures it "just prior to ball contact". Garmin calls it club head speed. It is the starting point for distance.

Smash factor

Ball speed divided by club speed. Foresight calls it efficiency: "the ratio between club head and golf ball velocities to determine the quality of the ball strike". It's calculated, not measured, so a unit needs both speeds to show it. A centred driver strike gets close to 1.5.

Angle of attack

Whether the club is travelling down or up into the ball, in degrees. Uneekor describes it as "the up and down movement of the club head at the time of impact", measured against the horizon. A positive number is hitting up, a negative number hitting down. Irons are usually hit slightly down.

Club path

The direction the club head is moving at impact, left or right of your target line. Foresight measures it "in a horizontal plane relative to the target-line". In to out is positive, out to in negative, on most units.

Face angle

Where the club face points at impact, against the target line. Foresight calls this face to target. It decides most of where the ball starts.

Face to path

The difference between face angle and club path. Foresight says it is one of "the main components in generating side angle and the curvature of the golf ball". A face open to the path curves the ball right for a right-hander; closed to the path, left. Some units show it as its own number; on others you work it out from face and path.

Dynamic loft

The loft on the face at the moment of impact, which is rarely the loft stamped on the club. Uneekor defines it as "the amount of loft of the club face at the center point of impact". It is mostly found on high-end camera units and on radar with a full club package.

Which units we sell measure which

The table on this page lists each launch monitor against the seven numbers, from its maker's own spec page or manual. Three patterns stand out.

• Most camera units beside the ball need a sticker or marker for club data. The Garmin Approach® R50, Foresight GC3, Uneekor EYE MINI and MINI LITE, Square Golf and Square Golf OMNI all do. Ball data works without them.
• Radar units need no stickers, because they track the club head directly. The Garmin R10, FlightScope Mevo Gen2, Full Swing KIT and Golfzon WAVE all read club speed this way.
• Some club numbers sit behind a paid tier. The Mevo Gen2's club path, face to path, face to target and dynamic loft come with FlightScope's Pro Package, which FlightScope says is a one-time purchase linked to the unit for life. The MLM2PRO's measured club path and angle of attack come with Rapsodo's Core membership. A GC3 bought in ball-only mode needs Foresight's club tracking purchase to unlock club data.

Measured or estimated

Square Golf's manual is unusually clear about this. With the club marker 20cm up the shaft, club path and attack angle are measured. Face angle and dynamic loft are estimated. The OMNI is the same for face angle and dynamic loft, and adds measured club speed and impact point once both its shaft and face stickers are on.

Foresight draws its line at the number of markers. The GC3 reads one marker on the face, which Foresight calls 1-dot data: club speed, smash factor, angle of attack and club path. Its 4-dot data adds face to path, dynamic loft, lie angle and impact location, and the GC3S manual says 4-dot data "is not offered on GC3 or GC3s". That is GCQuad territory.

Uneekor's EYE MINI and MINI LITE manuals list four club numbers: club speed, attack angle, smash factor and club path, and say stickers are required for them. Uneekor's comparison page lists no face angle, face to path or dynamic loft on either.

What I'd look for

1. If you only want to play courses, ball data is enough. Club data is a bonus.
2. If you want to fix a slice, you need club path and face angle, or face to path. That rules out the GC3 and the EYE MINI, and means the Pro Package on a Mevo Gen2.
3. If you hate fiddling with stickers, look at radar, or the SkyTrak ST MAX, which SkyTrak says needs no club or ball stickers.
4. Check what the software shows. A unit can measure a number that a third-party simulator doesn't display.

For the ball side of the shot, see ball data explained, and for how to fit stickers properly, balls and tracking stickers.