From my post: "If we have a stable of good RB's, where they can spell each other off, and we also want to have a strong passing game, isn't 15 or so carries a pretty good number considering those stated presumptions?"

I think the words "if" and "presumptions" in the sentence clearly indicate that as a "wish" or a "hypothetical" which address how often we want to be handing to anybody from our RB position group (hopefully not too many "crappy sports lingo and cliches" here in this clarified statement to bruise your sensitive ears/eyes).

IF

1a : in the event that
b : allowing that
c : on the assumption that
d : on condition that

2 : WHETHER "asked if the mail had come" "I doubt if I'll pass the course"

3 —used as a function word to introduce an exclamation expressing a wish "if it would only rain"