Glenn Roeder is one of the worst managers ie ever seen. After Iffy Onoura off course !
I know he might not be the most charismatic bloke but I can't see how you can say that. His record with Watford, West Ham and Newcastle is actually not at all bad, although with all three clubs it follows a bit of a pattern, a season of looking really good and finishing above expectations, followed by a season where the side has a few injury problems, no resources are available for stregthening, and it all goes pear shaped.
There are dozens of managers who've been a lot worse, and a lot of them have managed us in recent years.