I just did some research and saw that during the entire Tim Duncan Era, the Spurs have had a winning percentage of at least .600 or better EVERY SINGLE YEAR, with last season being the worst. In other words, for 14 years in a row (including the current season), the Spurs have won at least 60% of their regular season games. That is AMAZING!! I wonder if that's an NBA record. If not, it has to be close.
I looked to see if any of the other best-of-the-best, all-time greats could make that claim, and could find one, not even Kareem or Bill Russell. Tim Duncan, as far as I know, is the only one who has accomplished that feat.