Junior/Senior League, Ages 13 to 18 (Mustang 13-15 and Pony 16-18) - The diamond size can range with a 54-foot mound regulation (60'6"), and bases are 80 or 90 feet. While players will always work on the basics, fielders should have a working grasp on double plays, cut-offs, and defensive strategies for limiting offensive base advancement. Pitchers will continue controlling the runners, as will the catchers. Catchers will start understanding how to control the entire defense by calling plays and pitches.