How is a speed index calculated?
A speed index rating is calculated by averaging the three fastest winning times for three consecutive years at each distance at each track. This average is equal to a 100 speed index. If any of the fastest times averages are slower than the minimum standard time, the minimum standard is used to determine speed indexes at that distance. Speed index points vary according to the distance of the race. (For example, each speed index point at 440 yards varies from the 100 speed index time by .044 forty four-thousandths of a second.) A chart defining these variances appears in the AQHA Official Handbook of Rules and Regulations.
