Questions
For players, parents and coaches. If yours isn't here, see what it can't do yet or email contact@sagittaltennis.com.
Getting a good report
What do I need?
A phone, something to keep it still (a tripod, a bag or a fence), and 8 or more shots. Film side-on from 5 to 6 metres, whole body in the picture. The filming guide shows the set-up.
Which shots does it analyse?
Forehands, backhands and serves. Each shot it finds gets its own scores, and the session gets a Swing Score out of 100.
Does it work for left-handers?
Yes. It works out which arm holds the racket from the swing itself.
Does it work at night or indoors?
Yes, if the player is clearly lit. Dark or grainy video gets a warning. Echo and noise from other courts don't matter.
Can I upload a clip someone sent me on WhatsApp?
Use the original from the phone that filmed it if you can. Messaging apps compress video, which can throw the scores off. Heavily compressed clips get a warning.
It missed a shot, or counted one that wasn't a shot. Can I fix it?
Yes. In the "Shots found" list under your video, use "Not a shot" or "Add a shot here", and the report is rescored. Mark a shot "On the run" to keep it out of your scores. You can do this for 24 hours after uploading.
Reading your report
What does the Swing Score measure?
Your movement on groundstrokes: head stability, balance, and how low you load and hold it. Stance width, weight transfer, your front leg and contact point are shown too, but not scored. Serves use leg drive, contact height and shoulder tilt. Not racket speed, spin or where the ball went.
Is a high score the same as being a good player?
No. A club player with sound fundamentals can score close to a professional. Use it to track your own movement over time, not to rank players.
How accurate is it?
It's coaching-style analysis from one camera, not a lab test. Every change is checked against shots labelled by hand, and the report flags readings it's less sure of. See what it can't do yet.
Why do you ask for my height?
To turn the picture into real distances, and so a smaller player isn't judged on an adult's distances.
Does it replace a coach?
No. It shows what your body did on each shot and suggests one thing to work on. A coach sees far more: tactics, the ball, how you feel. Bring the report to your coach.
Juniors and parents
Can juniors use it?
Yes. A parent, or a coach with the parent's consent, should do the upload. Scores allow for height. Most of our test footage is of teenagers and adults, and we're still checking junior footage.
Is it safe to upload a video of my child?
Each report sits at a private link that only you can share. The original video is deleted after 24 hours and everything else after 14 days. We don't sell data or run advertising trackers. The details are on the terms and privacy page.
Coaches and clubs
Can I analyse a whole squad?
Yes. You can upload several clips at once, one per player, and each gets its own report.
What should I tell players and parents before filming?
What you're filming and why, that the report is a coaching aid rather than an assessment, and how long videos are kept. For under-18s, get a parent's consent first.
Does it cost anything?
No. Sagittal Tennis is free to use.
Privacy
Where does my video go, and for how long?
It's analysed on our server. The video is deleted after 24 hours, the report after 14 days. With an account, a short score summary stays in your history until you delete it.
Who can see my report?
Anyone you give the private link to, and no one else. Treat it like any private link.
How do I get a result deleted early?
Email contact@sagittaltennis.com. With an account, you can delete everything yourself from My progress.