New theory to why Tidus is good at holding his breath: He cried about his dad so much that all the sharp inhaling over the years conditioned his lungs, thus training him to be a Blitzball player. In fact, Jecht was deliberately being an asshole towards Tidus for the sole purpose of turning him into a star player using that technique. His ploy worked, and it gave him an excuse to excessively drink, which is always a plus.