Arm Speed Analyzer vs. Stalker Radar Gun
Professional Radar GunThe Stalker Sport 2 is what MLB scouts point at pitchers, and Arm Speed Analyzer is a free app that reads the motion of your phone or watch. They're not really built to do the same job — here's exactly where each one wins.
The Race
Accuracy
A Stalker Sport 2 reads release or plate velocity within a tenth of a mile per hour — the gold standard scouts and recruiters trust. Arm Speed Analyzer measures device motion, which is great for spotting trends but isn't a certified mph reading.
Cost
A Stalker Sport 2 is a serious investment built for programs and scouts. Arm Speed Analyzer costs nothing and runs on the iPhone or Apple Watch you already own.
Setup
A radar gun needs someone standing behind the catcher or mound, aiming it directly along the ball's path. Arm Speed Analyzer just needs the athlete wearing a watch or holding a phone — no second person required.
Sports Covered
A radar gun is built to clock a projectile — a pitch, a serve, a batted ball. It doesn't help you measure a golf backswing or a tennis groundstroke's racket speed. Arm Speed Analyzer reads the athlete's motion directly, so the same setup works across sports.
Recruiting Credibility
If a number needs to go on a recruiting profile or in front of a college coach, it needs to come from a radar gun. That's simply what the sport trusts, and no app changes that.
Which Should You Use?
Choose Stalker Radar Gun If…
you need a scout- or recruiter-verified velocity number, you're running a program that requires consistent radar readings, or the number needs to go on a recruiting profile.
Choose Arm Speed Analyzer If…
you're training on your own, want to see whether your speed is trending up week over week, and don't want to spend over a thousand dollars to find out — across baseball, golf, tennis, pickleball, or disc golf.
Frequently Asked Questions
Can Arm Speed Analyzer replace a Stalker radar gun?
No, and it isn't trying to. A Stalker gun measures actual ball velocity to a tenth of a mile per hour; Arm Speed Analyzer measures the motion of your device. Use the app for free daily training feedback, and a radar gun when you need a verified number.
Why is a Stalker radar gun so much more expensive than an app?
You're paying for dedicated radar hardware built and calibrated for one job — clocking projectile speed to scout-grade precision from up to 300 feet away. A phone or watch already does other jobs, which is why a motion-sensing app can be free.
Track Your Arm Speed for Free
No setup, no subscription. Just your iPhone or Apple Watch.
