"It's supposed to be fun, the man says 'Play Ball' not 'Work Ball' you know." Willie Stargell
Hall of Famer Bob Lemon once described baseball as "a kid's game adults just screw up."
In other words, when they're 6,7,8 years old, LET THEM ENJOY playing baseball. Who cares if it's with whiffle balls, incredaballs, etc: LET THEM HAVE FUN!!