What does it mean to "overrate?"
to rate or praise too highly; overestimate
No, it does not mean "bad," as many people tend to perceive it as when they think emotionally instead of logically. We need to know 2 things before we can answer the question as to whether or not BJ Penn has been overrated:
1) Where was he rated? What did people think of him? Where did they perceive him to be?
2) What has he accomplished? What do the results say? How has he performed?
After that is the easy part. How do those 2 answers match up? That will tell you whether he's overrated, underrated, or rated just right.
Let's start with question #1:
All signs point to BJ having been rated extremely high. Look at past divisional rankings, look at past pound-for-pound rankings, and just look at what people perceived him as being. It all points to being in the elite P4P top tier. He was thought of as being right there with Anderson Silva, Georges St. Pierre, and Fedor Emelianenko. This isn't to say that everyone ranked him there, just that in general, that's where the public ranked him. Very high praise. Did he match that praise with performance?......
Now question #2:
Now since we're comparing him to such high standards, I'm going to mostly be sticking with the big stage moments. BJ has fought in multiple weight classes. Let's separate his lightweight and welterweight careers.
LW: Let's be honest.....this division hasn't really been all that impressive. It's a young division. It hasn't yet had time to accumulate top, consistent contenders. This is probably the main reason BJ left the division multiple times. There simply wasn't much there. His top LW victories are over Gomi and Sherk. To me, those 2 stand out far above anyone else. Not exactly the work of a top tier P4P legend, though. But let's look at the rest of his career.....
WW: I don't think anyone can argue just how much better this division was compared to the LW division. But BJ's prospects excited many people. They felt he could move up and compete with the best the WW division had to offer. Did you know that if you just count WW matches vs highly ranked contenders, BJ Penn only has 1 win? Sounds crazy, but it's true. It also happened to be in his 1st WW match. Yes, BJ beat Matt Hughes. But that loss would go on to be avenged by Hughes. It seems common that when 2 fighters split 2 matches (a win and a loss for each), that usually it's the winner of the 2nd match who's the better fighter. And yes, I'm aware that the trilogy among these fighters recently concluded, but that wasn't the same Matt Hughes. He was 37 years old as opposed to 32 years old when they fought the 2nd time.
Another thing that stands out is the way in which Penn has lost 2 of his matches. In both rematches against GSP and Edgar, Penn was dominated. It's one thing to get caught and submitted or knocked out. It's another to just get run over in a lopsided decision.
I'm also aware of the various excuses Penn and his hardcore fans come up with; grease, lack of motivation, out of shape, past his prime, etc. As ridiculous as they are, they do go to show just what these same people expected of Penn. When he didn't match those expectations, there had to be reasons given for not doing so. This just adds more fuel to the "overrated fire."
As stated before, potential matters, but performance matters more. We can't give credit to BJ for what we thought he was capable of doing. We have to give him credit for what he's actually done. He was a very good-to-great figher. He certainly feared no man. But that fearlessness and the results of those challenges taken show that Penn overestimated himself. He thought he could be the best fighter of all time and taste the gold of every weight class. But the facts show that he couldn't even handle his own lightweight division. His latest change in weight wasn't even because of his lack of worthy opponents.....it was because he was no match for the LW champion.
I think it's easy to see that when comparing the conclusions for the above questions, BJ Penn has clearly been overrated.
EDIT: To clarify my final view of BJ, I think he's a very good-to-great fighter who deserves to be in the Hall of Fame and ranks somewhere between Rich Franklin and Randy Couture.