The NBA playoffs are in full swing, which means there’s a lot of talk about officiating in professional basketball. How the referees call games and how different those calls are in the postseason compared to the regular season tend to make up a large part of NBA discussion this time of year. Beyond that, all it takes is one big call in a huge moment to launch days’ worth of discourse about refereeing in today’s NBA. Thus, Wednesday brought some notable news—the NBA Players Association had released a ranked list of all the referees employed by the NBA. As far as we can tell this is the first such referee ranking the NBAPA has released to the public. The ranking separates the officials into three tiers, with Tier 1 being the best and Tier 3 the worst.…