Many top jockeys were born to the saddle, hailing from racing backgrounds, and blessed with the advantage of early introductions to riding. Such was not the case with Jorge Chavez, who had never even been on a horse when a friend took him to the races in Peru in 1981-at the age of 20. The tiny Chavez-at 4-foot-10-was soon inspired to try his own hand at race riding, the result being back-to-back Peruvian jockey championships in 1986-`87. Ambitious and ready to tackle the North American sport, Chavez turned up in Florida in 1988, but spent much of his first season sitting out from a series of suspensions. The situation improved for