User blog comment:Eduardovongola/Renji Overpower/@comment-1268838-20131228183426/@comment-26420452-20131229072140

Well, first, I agree that Rose has been a captain for little time, but we can't say the same for Kensei and Shinji, in fact we can deduce the latter might've more than a century in captaincy.

Secondly, you should take into account the promotions that were made after Aizen's defeat. If Renji was that good to begin with, he'd been promoted instead of one of these three Visored. So, Renji got that good only recently, while training in the Royal Guard.

And finally, regardless of how much stronger Renji has got, being a captain has become just having the right to wear a haori. Rose and Kensei shouldn't have been defeated so shamefully.