The Patriots today announced that they will not hire a defensive coordinator to replace the outgoing Dean Pees. Bill Belichick will be de facto coordinator. Of course, Bill Belichick is also the de facto offensive coordinator. The Patriots will be the first team since... well, since anybody can remember to have no official coordinators. Belichick can't possibly run things on both sides of the ball, so this probably turns QB coach Bill O'Brien into the new de facto OC, the same path Josh McDaniels traveled.
Some people may hold up this decision as an example of Belichick's colossal ego. "He thinks he can run the whole team without coordinators!" I don't think that's the case. The leading candidate to replace Pees was rumored to be LB coach Matt Patricia. However, a lot of observers felt that DL coach Pepper Johnson wanted the job as well. By going a year without a coordinator, Belichick can keep both Patricia and Johnson on staff, not offending one by promoting the other. Now, eventually, Belichick is probably going to have to make one of these guys the coordinator. But at least he gets another year to decide. The only question might be: Why not give Bill O'Brien the official promotion to OC, which wouldn't offend anyone?