Originally Posted by JCTexan
Six should be fine regardless. That leaves room for a QB, WR, RB, TE, Kicker & a defense if you so desire. You don't need three RB's or WR's on your bench just because that many are starting.
You mentioned the 6 bench spots for QB, WR, RB, TE, Kicker & a defense. Say your starting WR and RB are on bye. Then you take off the WR/TE and WR/RB slots to fill the starting WR and RB. What is then being used to replace the WR/RB or WR/TE slots? You can use the TE on the bench, but what about the other one?
Situations like the above and many more can be resolved with 2 more bench spots.