Place players, cones and a net on the diamond and write up cutoff-and-relay, double-play or bunt-defense drills ready to print.
Baseball defense is entirely positional — a relay depends on the outfielder's arm and the cutoff man's position, a double play depends on the shortstop-to-second-to-first sequence — so the designer is laid out on the diamond itself, not a generic rectangle, letting you place fielders exactly where a real defensive alignment puts them.