1. The only time BJ Penn has ever faced someone with intensity similar to Diego, he lost. Georges St. Pierre destroyed him. Look for Diego Sanchez to have a similar gameplan.
Look for Deigo to be unable to do anything similiar to GSP because of the fact he is not as big, not as strong and is nowhere near the caliber of wrestler or grappler that GSP is.
2. Better standup - Don't hate, its true. BJ Penn has good standup, I'm not neglecting that, but I don't think it is as good as Diego's. He does not have as much power in his punches, and isn't as quick. Diego Sanchez throws FAST. If this fight stays standing, BJ Penn will lose.
Are you kidding? BJ is one of the 5 most accurate strikers in the UFC, probably has the best boxing bar none and your saying a guy that leaves his chin wide open and misses over 50% of his strikes has better stand up?
3. Better wrestling - BJ Penn has world class BJJ, but his wrestling ability is not as good as Diego's either. The Nightmare has very good wrestling, and I understand he was outwrestled by Jon Fitch and Koscheck, but that was at 170 and has nothing to do with BJ Penn. Since stepping down to LW, Diego looks like a different fighter.
Diego has never beat anybody with decent wrestling, out of 100TD attempts BJ sprawls 100, Sanchez's TD's are average at best against the UFC's best TD defense, on the other hand you have Sanchez's average TD defense (Guida took him down multiple simes and Guida has excellent top control not awesome TD's) and the fact that BJ has almost always been able to dictate the fight, is he wants to take Deigo down he will, if he wants to stand they will.
4. More heart - This is based on opinion only, but I have the right to my own opinion and it's just how I feel about the matter. Diego has expressed time and time again how badly he wants this win, and all BJ Penn can talk about is how he loves to fight. It's almost as if Diego Sanchez lives and breathes because of fighting, and BJ Penn does it for fun. I'm not saying doing it for fun is a bad thing either, I'm simply just comparing the two and basing my opinion on it.
I have always wanted a million dollars, sometimes wanting it is not enough.
5. Defense - Diego Sanchez has very good defense. To my knowledge he has never been finished in a fight. And you will say that he has never faced an opponent with the level of BJJ like he will against Penn, but HE HAS! If you can remember correctly, he faced Nick Diaz on TUF finale and WON THE FIGHT. Nick Diaz is on the SAME LEVEL as BJ Penn when it comes to submissions, you're ignorant if you disagree.
If you think the Nick Diaz that fought Diego is anywhere near as good a fighter your dreaming, the Diaz that Deigo beat also lost to Sherk and Joe Riggs. BJ is so much more well rounded and dangerous that Nick Diaz its really not even funny,
Diego has never beaten a wrestler as good as BJ, never beat a grappler as good as BJ, never beaten a BJJ guy as good as BJ and never beaten a striker of BJ's caliber, Diego has cardio, well so did Sherk, wasn't enough. Bottom line is Diego brings nothing Penn hasn't already beaten somebody better at, BJ will be the best Deigo has ever faced in almost every facet of MMA, sorry but your boy has not chance.
Diego Sanchez will be BJ Penn's NIGHTMARE
Maybe afterwards if you send my a PM I can be nice and help you get your credit count back up, hope you didn't bet to much on this hail marry.
P.S. Hope you enjoyed my reasoning, this was not intended to put down BJ Penn in any way, it's just my opinion on why I think he will lose the fight.
I enjoyed reading but perhaps you need to quit drinking in the middle of the afternoon?