[Artmasterx]

Close...

It is the % difference from the average of the AS, BS, CS, DS, and ES class leaders for that event. Think of it as an average best time of the day for BMW's on street tires. (this is shown in the "average best" line). So you are not referenced to your class alone; the broader average probably smooths out some of the noise that would otherwise be present.

To get the value on the plot, take your average (best AM and PM average) and subtract the "average best" for that event. Then divide by the "average best" and multiple by 100 to get a percent... and BAM... you got your number.

# on plot = ([Your average] - [average best])/[average best]*100

Hope this helps.