We've been using the pocket radar for a long while now. Being that speeds vary widely, it's important to use one (and only one) to monitor progress. That said, we own the world's stingiest radar, so top speed is always lower than any other radar, but it's also an incentive. When friends tell me their DD throws 60+mph I break out my radar and watch the excuses fly.
She’s barely 10 yesterday at pitching class she was cruising at 38mph her speed decreased significantly after a line drive to her throwing hand(thought it broke her elbow, thank god it didn’t) it’s been a month and I can tell her speed decreased, max she had yesterday was at 41