You may want to refer to another post on basketball and race, which I wrote as a kind of introduction to these kinds of things.
Back in the 1980s, I was playing a lot of basketball and as always, I noticed a few language trends. One of them was the use of the familiar term, "cuz" by one player toward another. I assume it is a short form for "cousin" but that didn't mean the players had a common grandparent. It was for lack of a better description, a term of endearment. I suppose it could be compared to the 1970s use of the terms, brother or bro. It sounds corny today but people did talk that way back then.
One day I was playing at a particular playground and remember one particular player referred to almost everyone as cuz. He didn't seem to have any discretion or sense of over-usage of slang or maybe he had just learned the term himself earlier that week and couldn't get it out of his head. In any case, I was the only white guy there and waiting for the next game, which I had called. This cousin-of-everyone was in the current game and while I waited for next, I watched and listened out of curiosity to find out that he referred to every player (teammate and opponent) with that term. He offered direction to other players by saying things like, "I'm open, cuz," or "over here, cuz," or "this way, cuz," to everyone in the game.
My experience at that particular court had been that pickup games were normally played until 13 points so when one of the teams scored the 13th basket, I stepped on to claim next game. But they kept playing and the extended-family-guy pointed out to me that the local custom was that the first game to kick off the evening was usually played until 16 points. He said to me, "Game goess to 16, Chief." I wondered briefly why he didn't call me cuz, but it made sense. There was no way we shared any immediate relatives--at least as far as he was concerned.