I don't think Sanchez will beat BJ Penn. With Penn as commited as ever, enjoying training and fighting and wanting to form a legacy I think he'll beat Diego fairly comfortably. However, I don't see how having immense mental strength which has allowed him to make the most of his abilities and become one of the best fighters in his division is a negative.
This mental strength has allowed him to rack up a seriously impressive 21-2 record in his MMA career, with his only 2 losses coming to top tier fighters in Josh Koscheck and Jon Fitch, and neither of those 2 guys could finish Diego. He's beaten Jorge Santiago, Kenny Florian, Nick Diaz, Karo Parisyan, Joe Riggs, Joe Stevenson and Clay Guida just to name a few. That's an impressive list of guys to defeat right there.
I honestly believe Sanchez offers BJ Penn a far greater challenge than Kenny Florian and Joe Stevenson, and I expect the fight to be a war. I see BJ coming out on top, fairly convincingly, but you never know what Diego's going to bring to the table, I'd certainly love to see him pull off a win. I like Diego Sanchez alot. YES!