Still, it has to be, right? Three strikes and you're out is a concept unique to baseball. For it to become part of basic jurisprudence with no influence from the only other thing that uses the idea strikes (!) me as highly unlikely.
And really, reader, let's take a moment to recognize how ridiculous this is. Does the soccer-mad UK have a 'two yellow cards mean exile to Europe' law? In Indiana, arguably our nation's most basketball-obsessed state, is the 'three strikes' concept adjusted to 'five fouls'?
Whatever the answers to those questions may be (editor's note: no and no) we still have the 'three strikes' concept to think about, a controversial element of our legal system that many feel reinforces bias against black offenders while doing next to nothing to make America a safer place to live. And that it exists purely due to a fluke involving the rules of a sport that became popular enough to be referred to as "America's pastime" despite the sport's top professional league excluding black players until 1947...
Actually, when I think of it that way, I suppose that if the law were going to borrow from any sport, it would have to be baseball.