Man, whatever the situation is, if ur in the 50s at the center and u have no back players be ready for a mugging. Being in the center, especially behind a huge 50, ur setting up a blind spot that the other team will whore to the full sense of the word, regardless of whether or not u have a full team. Now, obviously, if there is a weakness in their team, like a back player/front player gone from one of ur tapes then it kinda ups ur chances, because it makes it slightly easier to guess which side of the field offensive moves will be played.
The simple fact remains though, if u get into that kinda situation there IS nothing u can do but wait for a mugging (Because of the ludicrous blind spot). Personally, I would go off on a spree and go down in glory, rather than a bitch at the mercy of a mugger.
Front players in 50s rely soley on back players to tell them where the players are and stop any moves being made on them. If thy are taken out its pretty much game over.
Something which helps with these situations (i think) is imagine that ur on the other team: You've taken out their back players and there are 2 guys in the 50, how would u get them out. When u know that, u'll know what to look out for.
Man, I'm talkin to ya like ur a stranger!
Mak*D, man.....the 50s ;-)