A session that comes back with far fewer shots than you hit is nearly always a recording story, not a tennis one. Four causes cover almost every case.
The camera could not read the court. The most common cause. A phone set too low, angled oddly or cropping the far baseline degrades detection sharply. Put your footage next to Where to put your phone; the fix is usually thirty seconds of repositioning next time out.
The ball was genuinely hard to see. Faded balls on a similar-coloured court, heavy silhouetting from low sun, rain on the lens. Light, weather and court surfaces walks through each one. Fresh balls alone solve a surprising amount.
The phone moved. A knock or a slow slide mid-session can spoil a long stretch of footage. The stable portion still counts. Wedge it better next time.
It is us. Sometimes a good recording comes back thin anyway. That is our problem, and we want to see the footage, because the awkward cases are how the system improves for everyone.
If your recording looks reasonable and the numbers do not, message the team below with the session in question. We will look at the footage itself and tell you what happened.