Is there a tangible benefit to playing different youth sports at different times of the year, even if a player intends to specialize on one?
There is a benefit to playing different sports, much in the same way that it is beneficial to cross-train when you are a single-sport athlete. When participating in other sports, there are often different movement patterns, which means a different usage of muscles and will allow overworked areas to rest, or at least be worked in a different way. It would not be advisable for a baseball pitcher to spend his time away from baseball playing football as the quarterback, however. The sport may be “different,” but a large portion of the athletic activity involves the same motion and therefore is not letting his arm rest. There are many ways that athletes can become “better” without doing “more” of the activity. A pitcher does not necessarily become a better pitcher by simply pitching more and a runner does not become a better runner simply by running more.
There are many ways that athletes can become “better” at their sport by doing other activities to strengthen, stabilize, and support, such as by lifting weights in a targeted manner with emphasis on the kinetic chain of their athletic motion (i.e. a baseball pitcher strengthening his legs and core as a means to increase the velocity of his pitch). Studies have shown that athletes who participate in multiple sports are often injured less and do not experience episodes of “burn-out” as often.