This entry is not technically philosophical, but more about the state of philosophy education, particularly at the graduate level.
To the extent of my knowledge, most of the great coaches that I am aware of (e.g. Pat Riley, Phil Jackson, Larry Brown, Joe Torre, Bill Parcells, Jimmy Johnson, Joe Gibbs, Mike Holmgren, et al) were not superstars during their tenure as players. It also seems that all-star/hall of fame players don't make very good coaches (fewer examples come to mind, but notable ones include Magic Johnson and Isaiah Thomas).
This seems to make some intuitive sense. Guys that ride the pine are the ones who have to work hard in order to develop the skills that they need in order to succeed. They weren't blessed with natural talent, so they learn everything the hard way. This puts them in a better position to teach others what they've learned. All-stars, however, can lean on their natural talents and therefore can get away with not having to learn the finer details of the game. They have an intuitive feel for the sport, whereas the benchwarmers need to figure things out at a much more explicit level. Because of their innate abilities, however, the all-stars have a difficult time explaining the mechanics of their success to others, hence they do not make good coaches.
I think there is a relevant analogy between sports and the academic world.
I hear lots of stories about well-known philosophers who are terrible teachers/advisors. I think these individuals often have a natural feel for philosophical discourse. They can run through arguments without having to make every step explicit. Because of this, they can stay abreast of the cutting edge of the debates and make a prolific number of contributions. However, they are also relatively less able to relate this knowledge to others who are philosophically less mature. It seems to me that those who are not as talented, who have to learn positions and arguments the harder way, by taking them step by step, are usually the ones who end up being better teachers. They are the ones who can communicate the subtle points of arguments in a manner that is comprehensible to the average graduate student, because they had to explain the same material to themselves.
There is, however, a point where the analogy breaks down. In sports, there is a distinction between coaches and players. There are individuals who are coaches, and there are those who are players, and there is not much overlap between the two at any given point in time. However, in academics, this is not the case. Members of faculty are both coaches and players at the same time, in that they take on the dual roles of teaching and reasearch. I think this is to the detriment of the students.
From my understanding of how the system works, a large determinant in whether one finds placement after completing a PhD is one's letters of recommendation from their advisory committee. There seems to be a positive relationship between the likelihood of finding a job and the academic reputation of the people writing your letters of recommendation. Thus, many would-be philosophers find themselves compelled to work with the most famous people in their department, and these famous individuals are often the ones who end up being substandard teachers. So the education and development of these students suffer as a result.
Now of course I am making generalizations here, and I am sure that there are some famous philosophers who are also excellent teachers (several come to mind immediately). We should be thankful for them. But I think that the number of famous philosophers who are bad teachers is high enough to make this a legitimate concern.
It would make more sense to me for the philosophical community (perhaps the APA) to recognize those faculty out there who are gifted teachers. Such recognition could be possible by tracking the career progress of their students (i.e. their publication record, presentations, and other contributions to philosophical discourse). Individuals whose students demonstrate such consistently good work as professional philosophers should be recognized for it, and their letters of recommendation should carry more weight in the eyes of hiring institutions.