When Alex Poythress decides he wants to dunk the ball, he does it with a contradictory effortlessness. On one hand, the slams are so ferocious, so emphatic that you find yourself taking pity on the lifeless rims. On the other hand, he throws them down so easily, so naturally that one would assume he’s been doing it his entire life. As it turns out, contradictions come in twos. There was a time when Poythress couldn’t dribble the ball, much less dunk it; a time when his twin sister routinely beat him at his own sport, the neighborhood kids didn’t pick him and college basketball was a pipedream like it is for the other 99.9 percent of society.