Sporting News ranked the 16 playoff coaches prior to the playoffs and Stevens finished 5th. Ahead of him where (in order) Pop, Carlisle, Kerr, and Doc.
It's absolutely hilarious that Doc is ranked over Stevens.
Doc is a good manager of egos, and good at out of bounds plays. Other than that, he's just average. Give him great players, and he'll get solid results. Give him bad players, and he'll get poor results.
Stevens on the other hand gets the team to overperform.
Managing big egos and elite talent, and being able to bring them together as a team is an enormously difficult task. Not many coaches can pull it off. Doc can, and is one of the best at it.
Doc has failed as a GM, which was unsurprising. Even the great Pop has had help in that department. RC Buford is regarded as the best in the biz. But Doc is an elite coach.
But I love Stevens for this Celtics team, because it requires a different set of skills. And Stevens is a bit better at X's & O's and adapting a play style to get the most out of a bunch of role players. It remains to be seen if Brad can get a group of big time egos to mesh, he hasn't really been tested there yet.
Let's also not forget, Doc once upon a time won COY with a marginal Orlando team that overachieved much the same way the Celtics have the last few years.
Both are very good NBA coaches who have different styles, while sharing some similar attributes. The Celtics have been lucky to have had two really good coaches under Ainge.