It is similar and the refs, despite how it looks are graded every game I believe.
I don't recall where I came across it but this is what I heard a few years ago. The league kept trying to make changes to the way refs called the game but the more senior officials tended to ignore them, especially come playoff time. But the NBA wanted it called the same, year around, and began forcing/encouraging the more senior refs to retire. This purge was supported by the Players Association also as they felt old legs and old eyes couldn't keep up and call the game correctly. And so, for the past decade the average age of officials has continued to trend downwardly and as is the case with young players, young refs take a few years to get up to speed and even longer to learn how to handle the personalities on the court and on the sideline.