on the sac fly rule

BA Prof: And McGraw was the hall of fame baseball player. Played third base. Back then, players wore belts and there was only one umpire. So while the ump was watching to see if the infielder would catch the fly ball, McGraw would cheat a little and grab onto the runner's belt. Well, the runner got him by unbuckling his belt. History does not relate if his pants fell down.