One of the reasons I've always hated pitching machine and any drill that forces a hitter react abnormally to hitting a ball (quick fire soft toss) is one that forces a hitter to abandon proper sequence. Whatever drill you do, you need to allow the hitter some kind of recognition that a ball is being delivered to hit. It could be a hand motion, or some other kind of indicator, but it needs to happen. DD's coach use to do a quick fire front toss drill. DD would swing and finish her swing, next ball was coming before DD even had a chance to start her sequence again... that drill use to get me fired up.. do you want your kids to only swing with arms and wrist??? Sigh