One of the many curious things about the billion-dollar labor market better known as the NBA is how many of the world’s greatest basketball players were told at one point or another that they weren’t good enough.

They weren’t recruited by top colleges out of high school. They found themselves living halfway across the world eating borscht after they weren’t drafted by NBA teams. But when they finally made it to the league, there was one thing their unlikely backgrounds and vagabond experiences qualified them to do: play defense....