One of the repeated themes I read here is how the Spurs coasted through seasons and then turned it on during the playoffs to win their championsiphs. But, if you look at the records the Sprus had during their 4 championship seasons, you will find no coasting:
Here are the records for the Spurs' 4 championship seasons:
98-99 37-13 (lockout season)
02-03 60-22 (best in the NBA)
04-05 59-23
06-07 58-24
One year, I think it was 04-05, they were something like 19-13 heading into January, but then turned it around and finished with a top league record. I think it is safe to say that none of the four win-loss records above will be worse than what the Celtics finish with this year.