No but I think the fact that when they were both fresh BJ clearly was the better fighter illustrates he is more skilled, Diaz only came back to win the latter rounds because BJ showed up unmotivated and lacked the conditioning to continue the same for 2 more rounds. Diaz may have been the better fighter that night because he was in shape but BJ is clearly the more skilled fighter and if he was motivated he would have dominated that fight.
But that has been the story throughout his career hasn't it? When BJ wins, he dominates, when he loses he loses because of lack of motivation. I doubt anyone will deny that BJ Penn is an enormous talent, but that fact that people believe that he is almost unstoppable if motivated or well trained is frankly misinformed judging by his fight history. It's a cop-out really, one that makes him impossible to lose in the minds of his more rabid fans.
I consider myself a big fan but I don't fool myself into thinking it's a training issue or lack of motivation issue. It's a BJ Penn issue, it's a mental issue, and a personal issue. And it's an issue which should get judged as a whole when judging him as a fighter. BJ Penn isn't 16-8 but 24-0 if he were motivated, he's 16-8 period.
It is as much an attribute (a negative one) as lack of chin, lack of heart, lack of size, lack of mental stability or lack of anything else is to any other fighter, so why we judge him differently?
Nick Diaz is a better fighter, that fight proved that. BJ Penn is potentially, at least most of the time, the most talented fighter in the ring with whoever he gets in there with. That's why he was considered P4P for so many years. But is he a better fighter than Nick Diaz, at least at this point? No.