Some coaches use whiffle balls as a way to help players get more repetitions with their swings. Not only do whiffle balls break often, They can also potentially hurt if hit in the head. Smush balls just bounce off, no marks, no bruises. People throwing do not wear out their arms throwing them. You can hit Smush Balls into fences without damaging them. Use in rain, cold, snow, they are the perfect training aid.