What they actually do
The CT10s clip onto every club and pair with your Garmin watch. Take a swing, and the sensor plus GPS logs which club you used and where the ball ended up — no manual tagging, no typing scores into an app between holes. Put one on every club in the bag, including the putter, and the watch quietly builds your scorecard for you as you play.
Deadly accurate for scorekeeping — once they're broken in
After you've used them a fair amount, in conjunction with your Garmin watch, they're genuinely impressive for keeping score automatically. That's assuming you're not out there hitting things, throwing clubs, or hitting multiple balls off one tee — do that and you'll confuse the poor sensor. Play a normal round and it just works.
The catch: the better you get, the worse the advice gets
Here's the part that surprised me. When I was scoring around 150, the sensors were rock solid. As I improved — down into the 120s, and now regularly in the 90s from the senior tees — the club-distance advice started actively working against me. The sensors build their recommendations from your shot history, so old, worse-golfer averages stick around unless you reset them.
How I reset them
This is the fix that's worked for me every time my game has leveled up:
- Go to an indoor simulator (I use a TrackMan setup).
- Hit about 40 balls with each club.
- Throw out the best and worst shot from each set.
- Average the distances that are left.
- Write that number down and use it as your baseline for the season.
Redo this every time you feel yourself leveling up. It's a bit annoying to have to babysit a gadget like this — but honestly, needing to reset it because you got better is a good problem to have.
Pros
- Automatic scorekeeping across the whole bag, putter included
- Genuinely accurate once broken in
- Pairs seamlessly with Garmin watches for on-the-fly club advice
Cons
- Advice quality degrades as your distances change
- Requires periodic manual recalibration (simulator session)
- Can misfire if you're rough on your clubs mid-round
Who should buy these
If you're the type who wants real numbers instead of guessing, and you don't mind a once-a-season tune-up, these are excellent. If you want something that's truly set-and-forget forever, temper expectations — your own improvement is the thing that breaks them, and there's no way around that except checking in on your numbers now and then.