What does "third-string" mean in this context?

Question

When I was a little girl, Louis spent a lot of time with his third-string hoodlum buddies, guys with names like Izzy, Lazar, Harry, AI. They played cards for days on end and filled the house with clinking coins and schnapps glasses, thick masculine voices and the smell of cigars. Louis had been a prizefighter when he was in his teens, a fancy dresser and an outstanding dancer. I don't even know if he finished high school. (source)

I am familiar with the meaning of the term as defined in dictionaries, substitute player. But what does it mean here? What subtleties does it carry?

Answer 1

The idea is probably that they were petty criminals, with low rank and status within whatever formal or informal criminal hierarchy existed locally. (That hierarchy would be the "team" that the metaphor implies.) The author might also be implying that their direct involvement in serious criminal activity (beyond illegal gambling and the like) was only intermittent, just as a third-string player on a sports team rarely plays. So if this was a town or city with one or more organized gangs, they may not have been formal members.