Hey! Sorry for the late response I missed this question, Multi ball is a great way to work on keeping a short swing because you have less time and the recovery is important. Also focus on not using your shoulder, just think about the snap and the acceleration from the lower arm and elbow. The last thing is that if you are using your legs and body well then your arm will have to do less work and you can keep a shorted and more relaxed swing so be sure you are doing this well! Dan 🙂