Yes. Darrell Bevell is a middle of the road offensive coordinator. Despite his meek presence his play calling is extreme. In some areas he looks like a genius, an innovator, in other areas he looks mediocre and flatout clueless. There is no inbetween with Darrell Bevell.
Bevell is a big picture guy, and this is why I think he might be okay as a head coach. I think his game plans are imaginative, and filled with outside of the box thinking. He's a chess player, he understands the opposing defenses weakness and if need be he'll spend the whole game setting up certain plays that take maximum advantage of the opposing teams nature. You can just tell that he spends a lot of time watching game film, he is able to exploit even the most mundane behavior tendencies of certain teams. That is not a quality that you see in many offensive coordinators.
Unfortunately the fact that he is a chess player is also his most glaring weakness. Like a chess game, his play calling is slow developing. His goal is to control the middle of the board so to speak, and he places his pieces very carefully, and very deliberately like any chess player would so that he will set himself up for the mid game phase of chess. This translates to an offense that sputters for the first half, sometimes for three quarters. He spends too much time setting up his gambets, implementing his plots, and plans -- this translates to an offense that can't get out of its own way for at least one quarter.
What Bevell will do is call the same plays over, and over again, give very obvious looks and run with a tepid, predictable bland offense, then he'll start to capitalize around the second half. He will lull the defense into complacency, and then suddenly his offense will spring to life almost miraculously when the defense finally decides to take his gambit. That is what this offense is; a giant gambit.
Darrell Bevell sticks to the game plan even when it doesn't work. He doesn't know how or flat out refuses to adapt to the situation. This also means that his situational awareness is almost non existent. His play calling becomes hilariously bad on third and short, and goal line situations. He tries to use a scalpel when the situation requires a meat cleaver or visa versa. This leads to a middle of the road offensive coordinator.
Bevell is a genius in some aspects of the game, but sadly that is also his greatest shortcoming as an offensive coordinator. Strictly as in game planning he is one of the best there is, but when his desktop theories get tested in the real world they lead to mediocre results. Real games involve adjustments and situational awareness, both qualities he doesn't have. If Bevell was not the chess player that he is, he would be one of the worst offensive coordinators in the league. This is why he is a mediocre offensive coordinator and why he could possibly be a great head coach.