A few months ago, B.J. Penn was dominated by Frankie Edgar, losing all five rounds on all five scorecards, and it seemed as if he might just fade out of the MMA scene.

Last night, Penn knocked out Matt Hughes in 22 seconds and he looks like a world-beater once again.

But is Penn really back to his old dominant self?

Matt Hughes is a UFC hall of famer, and historically, one of the greatest welterweights of all time, but let's be realistic: he's 37 years old, and a win over him doesn't mean the same thing it did six years ago.

Not only is Hughes now many years past his athletic peak, but the new contenders are better fighters now than Hughes ever was, at least when it comes to overall skills.

Now, if you're asking where I'm going with all of this negativity, let me elaborate just a bit further.

A few weeks ago I wrote an article about the way people should measure wins and losses. When it comes to weighing the competitive value of a win or a loss, it really comes down to the opponent.

A few months ago Joe Lauzon looked like a titan against Gabe Reudiger, but looked bad in the second round against George Sotiropoulos last night. Despite those facts, I feel that the biggest difference is simply that in one case Lauzon fought a clearly overmatched Reudiger, while last night he faced one of the better fighters in the lightweight division.

In the case of Penn, while it's true that he looked flat-footed and slow against Edgar and quick and nimble against Hughes, it's a lot easier to look fast in comparison to Hughes than it is to look fast in comparison to Edgar.

Penn's win over Hughes tells me very little about how he would fare against the current elite UFC welterweights, who are all more well-rounded than Hughes, and it tells me even less about how he'd do against the faster lightweights like Edgar.

Of course, maybe you'll still disagree with me and tell me that Penn's improvements are objective, and aren't just illusions enhanced by the contrast to an over-the-hill 37-year-old. Okay, well even then there are still good reasons to be doubtful over Penn's future going forward.

The real truth about Penn is that while his talent has never been in question, his motivation is always a question. Always.

You would think that after losing in his first title shot, Penn would have come in extra motivated for his next opportunity, but instead, he ended up drawing against Caol Uno, a fighter he'd beaten handily before.

Later on, conditioning appeared to be an issue against both Georges St-Pierre and Matt Hughes.

Of course, Penn did rebound, but when he finally found himself in the biggest fight of his life opposite St-Pierre in the rematch, Penn couldn't muster up the energy to really get himself into good shape.

Two fights later, people are once again anointing him the greatest lightweight of all time, but then he looks flat in two consecutive fights against Edgar.

At this point in time, it should be completely clear that as good as Penn can look on any given night, you never know how good he's going to look in his next fight until it happens.

If you're a Penn fan, you better hope that the prospect of fighting Jon Fitch is enough to keep the mercurial Prodigy interested in fighting.