Most of the time Lou Brock is a slow-moving man whose idea of kicks is a morning glued to the TV game shows. But when he steps onto a baseball field, the fast-stepping St. Louis Cardinal left fielder is transformed into the most dangerous man on the major league base paths. The game's best base stealer, Brock at 35 last week closed in on the major league record of 104.

One of nine children, Brock grew up in Monroe, La. and spent three years as a math major at Southern University, before a $30,000 bonus from the Chicago Cubs lured him away in 1961. Once traded to St. Louis in 1964, he became what he was not in Chicago—a consistent hitter, an acceptable outfielder and an unnervingly clever base runner. This year, even though he is slowing down, he says his knowledge of pitchers more than makes up for the lost speed.

Off the field, he has met with mixed success. He was involved in an auto dealership that folded four years ago, and he made a TV commercial for a brand of chocolates that was ordered off the air by the Federal Trade Commission. (The FTC said that eating the candies might make people fat, instead of making them as fast as Brock, as the commercial suggested.) Other later ventures have been more successful. He owns a thriving florist shop and is associated with a sneaker manufacturer, to whom he sold a design for a special sole that gives powerful lateral traction—just what a thief needs for a quick getaway.