MyGolfSpy put twelve launch monitors against a reference system and published the part most buyers skip: the numbers do not fail evenly. Ball speed held. Across nearly every device, indoors and out, it stayed within one to two percent of the reference. Spin did not. Some of the lower-priced units drifted twenty to thirty percent off indoors. Launch angle, the metric almost nobody shops for, showed double-digit swings on the same machines (MyGolfSpy).
The reason is simple once you say it plainly. A launch monitor either measures something or estimates it. Ball speed is close to the clubface and easy to capture, so cheap radar and premium radar agree. Spin is harder. The lower-priced units lean on models to fill it in, and the model is only as good as the swing it was built to expect. When your swing sits outside that expectation, the spin number goes soft. The same is true of launch angle. The new Shot Scope LM1 makes the trade-off explicit, delivering steady ball-speed and distance reads while omitting spin and launch entirely rather than guessing at them (MyGolfSpy).
Here is why that matters more than it sounds. Spin is the number golfers chase hardest. Driver spin too high and the ball climbs and stalls. Too low and it knuckles down out of the sky. Wedge spin decides whether the ball checks or releases. So the metric people most want to fix is the one their device is least sure about, and almost nobody is told that when they buy. MyGolfSpy’s own framing lands it: the difference between a five-hundred-dollar unit and a five-thousand-dollar one is not how far the ball goes. It is how much trust you can place in the number telling you how it got there.
The honest response is not to panic about your equipment. It is to change what you do with a single reading. One spin number off one ball on one mat in one session is noise dressed as data. A golfer who reads it as a verdict will tinker with a shaft, a ball, an attack-angle cue, chasing a figure that moved because the machine guessed. The figure that means something is the one that survives repetition. Forty drivers across three sessions that all land near 2,900 RPM is a fact. A single 2,400 on a budget unit indoors is a maybe.
This is where the indoor caveat earns its keep. The widest spin errors in the test showed up indoors, where the ball never flies far enough for radar to watch the back half of its flight, and the unit has to infer the rest. Sim work is where most committed amateurs now log their reps, in the off-season and after dark. The convenience is real. So is the cost: the environment that lets you hit two hundred balls in February is the same environment where your least reliable number gets least reliable. None of that makes sim data worthless. It makes it data that needs a second look before you act on it.
So the discipline is unglamorous. Read trends, not points. Weight the metrics your device actually measures over the ones it models. Treat indoor spin as directional until an outdoor session or a longer sample confirms it. Notice when a number jumps in a way the rest of the session does not support, because a real change tends to bring company. Ball speed, smash, and carry usually move together when something genuine shifts. Spin that leaps alone, while everything around it sits still, is the reading to distrust first.
That is a lot to hold in your head while you are also trying to hit the ball. Most golfers will not do it. They will glance at the screen, see a number they like or do not, and react to one swing. The test is a useful reminder that the screen is not neutral. It has a confidence level it never shows you, and that confidence is lowest exactly where your attention is highest.