What happens next, and how long it takes

Uploading a video does not, by itself, analyse it. Analysis is a separate, deliberate step, because it takes real time on real hardware and because you may want to trim the clip or mark something up first.

Starting the analysis

On every throw card there is a lightning bolt control, ⚡, in the card's top-right corner next to the scissors and the pencil. That is the analyse button. Hover it and it tells you what it will do:

What the tooltip says	What that means
Analyze (no trim)	This throw has never been analysed. Press it to start.
Re-run analysis	Results already exist. Pressing it analyses the video again from scratch.
Analysis failed — retry	The last attempt did not finish. Press it to try again.
Re-analyze to apply tags	You have marked something up by hand, and those marks are waiting to be used. Press it to run again with them.
Starting… / Processing…	A run is already going. The button is disabled until it finishes.

If your video was uploaded and started analysing on its own

Invited accounts can have upload start the analysis automatically. If yours does, the card goes straight to Processing and you never need the ⚡ button for a first run — it is still there for re-runs, and for applying tags after you have corrected something.

Each analysis you run counts against the number of analyses your invitation includes. Re-running the same throw counts again. This is the reason What makes a good video is worth reading first.

Watching it run

While a throw is being analysed, its card shows what it is doing — the word Processing followed by the stage it is on — instead of the result links. There are seven stages, in this order:

graph LR
    A[Setting up] --> B[Preprocessing]
    B --> C[2D tracking]
    C --> D[3D reconstruction]
    D --> E[Analytics]
    E --> F[Report]
    F --> G[Viewer]

Stage	What is happening
Setting up	A graphics server is being started for your throw. Nothing is being computed yet.
Preprocessing	Your file is standardised — resolution, frame rate, rotation.
2D tracking	The hammer is being found in every frame of the video. This is the stage that decides how good everything downstream can be.
3D reconstruction	Your body position and the hammer's path are lifted out of the flat picture into three dimensions.
Analytics	Turns, support phases, speeds, angles and distance are computed.
Report	The numbers are laid out into the report you read.
Viewer	The 3D scene you can spin and scrub is built.

If a stage seems stuck for a long time, that is a prompt to wait a little longer or, if it does not recover, to run it again with the ⚡ button — not a sign of a crash.

How long it takes

A complete run on a throw of ordinary length has been measured at about 15 minutes end to end, of which roughly the first six minutes is Setting up — waiting for a graphics server, before any of your video has been looked at. If a server is already warm, that first part is much shorter.

Those are measured figures from real runs, not guarantees. A longer clip takes longer. Nothing is lost if you close the browser; the run continues without you and the card is updated when you come back.

When it finishes

The card's metric slots fill in — Speed, Distance, Duration, Turns — and result links appear: View 3D and Report.

You may also see a button reading "1 concern", "3 concerns", and so on. Click it and you get a table of what the analysis is unsure about, with three columns: the Issue, how serious it is (Severity), and a Suggestion for what to do. Concerns are not failures. A throw with concerns still has a report and a viewer; the concerns tell you which numbers to treat carefully and, usually, exactly what to correct.

The most common concern is sparse hammer tracking, and the fix for it is When tracking fails.

Next: Reading your report