I have followed the Celts since the 60's - three separate championship groups built by Red Auerbach who played most of their careers in Boston and won multiple titles. A long dry spell was broken by Kevin Garnett's team - a group brought together by Danny Ainge - who deserved much better than the one banner they hung in the rafters in 2008.
What all these teams had in common was consistency and mental toughness and discipline. If they had championship-level talent they usually played at a high level most games. Sure, every team comes out flat a few times every season, but that type of performance was an aberration for these previous title groups.
This current Celtics team is different because they have championship-level talent, but perform more inconsistently than any team of any sport I can remember, pro or college. Some games they decide to tighten up their offensive execution and shot selection and play beautiful, fluid basketball. Other games, they are a 3-point clanging, turnover reckless disgrace. When the team comes out with that high-energy, play-on-a-string defensive mindset, they can look unbeatable and when they do not, they are flat-footed and have the look of wanting to be anywhere but on a basketball court.
Then, of course, there is Joe "dazed & confused" Mazzulla, who was promoted into an impossible situation and has coached like it most of the season. Blame for that disaster should be shared equally by Joe, Brad and Wyc.
A slightly altered quote from the movie Bull Durham sums up this team perfectly, "Million Dollar Talent and Five Cent Heads."