Abstract: Described herein are ball devices that can be used for training athletes how to properly throw, and more specifically, that can be used to train softball pitchers. The ball devices described here, referred to as multi-balls, include two or more balls (e.g., softballs and/or baseballs): a primary ball, and one or more secondary balls. The secondary ball(s) can be attached to the primary ball in any number of different arrangements. The secondary ball(s) can be detachable from and re-attachable to the primary ball to allow for customization. The attachability/detachability can be achieved using any number of mechanisms, such as but not limited to a threaded connection. Multi-balls according to the present disclosure provide improvement over prior art double balls, including better customization, better weight distribution, better suitability for visual pitch analysis, and better suitability for less experienced/younger/smaller pitchers, among other improved capabilities.

Abstract: This disclosure relates generally to sport ball systems, methods, and devices. More specifically, this disclosure relates to weighted sport balls, such as softballs, baseballs, footballs, volleyballs, and basketballs, used for training athletes. Even more particularly, this disclosure relates to weighted sport balls with outer shells having seams. This disclosure also relates to weighted sports balls with seams that match regulation sport ball seams.