I'll try to make it simple, but I'm looking for a new job right now because I've not been deemed very good at teaching things to football fans and farm kids.
A 500 score for any of the lifts/runs is the average for an FBS football player that weighs the same as the person being tested. Above 500 is better than average, while below 500 is worse than average for that weight.
This is a guess that I could probably look up, but I'm lazy: the scale is based on a gaussian distribution where the mean is 500 but we don't know what the standard deviation is. My educated guess is the standard deviation is 50. Here are two examples given my S.D. guess:
Cam Taylor-Britt: 198 lbs, 525 lb squat, 557 index points
View attachment 3036
He's squatting more than 87.3% of BCS athletes at his weight.
Damion Jackson: 270 lbs, 644 lb squat, 608 index points
View attachment 3037
He's squatting more than 98.5% of BCS athletes at his weight.
Ford, does this help or make your head spin? Like I said, I've been told I'm not very good at teaching, so there's that.