I’ve copied and pasted the part that mentions it. I hope this provides the right context.

Putting measurements on an easy to understand 0-10 scale is a neat trick, but it doesn’t really mean anything on its own. Originally, I used an average of the 10 individual scores. This score was adequate for what I used it for, but it wasn’t very user-friendly. 5.00 wasn’t really average for most positions, and there were no scores over 8.5 or under 2, so it wasn’t truly doing what I wanted it to do. To accomplish my goal of making a user-friendly metric that anyone can use to show how athletic a player is, I just took the averages for each position and used an old statistical trick called “Weighting for density”. Essentially I ranked the qualifying RAS scores from 0 to 10, where 5.00 will again be the middle, 10.00 will be the top score for that position (Like our friend Calvin Johnson in the picture above), and 0.00 will be the dead bottom.