Performance Rates are an objective measurement of racetrack performance developed by the
Jockey Club Information Systems. Performance Rates assign a rate to horses based upon
beaten lengths - who beat whom and by how much - with some adjustments made to standardize
beaten distances to account for horses that are not pressed or eased in large fields.
Time is not a factor in Performance Rates, which are based on every start by every horse
in North America. Performance Rates are expressed in lengths around a theoretical mean of
zero. The average Performance Rates of the best horses in a given year are generally
about 30 lengths better than an average performance of the average horse.