On Apr. 15--the eighth day of Keeneland's 15-day Spring Meet--the Condition Book offers a new type of race: a "ratings handicap." Worth $84,000, the 6 1/2-furlong event for 4-year-olds and up is for horses with performance numbers (85-75) derived from previous performances based on speed, finish position, competition and other factors. Developed by Equibase, the Thoroughbred industry's official database, the ratings system was designed to simplify eligibility requirements, improve race competitiveness and attract larger fields. It differs from Equibase Speed Figures, which measure how fast a horse has run in...