I've always been of the opinion that there are very few genuinely good managers. Most of the rest are just ex-players who, in some cases, have been lucky enough to have it work out once for them, which is enough to keep them on the merry-go-round. Rarely do you see a manager go in and do a really, undeniably good job at 3 clubs. For starters the fact that almost all are ex-players means it's a limited pool. Having played the game will definitely be a slight benefit, but the skill set required to be a good left back, centre back, striker or whatever is totally different from that required to be a manager. It's no surprise that, although loads of players fancy a crack at it, not many are very good. Bruce has been bobbling about being mediocre at best for years and somehow keeps getting jobs. If you were a PL owner and wanted your club to progress, you just wouldn't touch him, you'd be better off taking a punt on someone unheard of tbh