An earlier version of this page led with a Session Load Score out of 100. It is not here now, because we could not answer the first question anyone asks about it.
Here is what it will be. A number computed after the session, from the components on the report, compared against the same athlete's own previous sessions of the same kind, and never against another athlete. What goes into it, and how much each part counts, is the part we are still working out. We are working it out by asking trainers what they watch for rather than choosing the inputs ourselves.
Two trainers have already told us something that changes it. Both said, without being asked, that getting better shows up as less of something rather than more. Fewer unnecessary dribbles. Fewer mistakes. A load score usually counts up.
One of them, Jonathan Simmons, runs a drill that does not end until the kid makes two in a row, twenty one times. A kid having a bad day does more work, not less. A score built on how much he moved would read his worst session as his hardest one and tell his parents he had a great day. We would rather find that out in a conversation than in a parent's inbox.
There is a harder reason too. A jump count can be checked against video. A heart rate can be checked against a chest strap. A single number built out of several unchecked numbers has nothing to check it against. That is a research problem and not a coding problem, and we are not going to pretend it is solved by putting a number in a circle.
What the demo is currently computing
The score on the demo is sample data and the weighting behind it is a placeholder, not the Slingshot algorithm. It is two parts: how many jumps per active minute, and how the session's minutes split across the movement bands. Jump rate carries 0.58 of it and the band split carries 0.42.
There were three parts until August. The third was sprint rate, and it carried 0.40, the largest single input. It is gone. The pod sits on an upper arm and cannot see the legs, so there was no sprint measurement behind it. The two that remain keep the ratio they had to each other.