Yes, there is sometimes a big difference between who you *want* to win and who you *think* will win. The two are not necessarily the same.
I actually like Sherk in this one. I don't think BJ will KO him; look at the vicious knees Sherk took right to the chin in his fight with Hermes Franca.
But I don't think he can 'beat' BJ Penn, either. I see this fight going the distance, with BJ hanging on in the later rounds by the last drop of his always-short gas tank. Sherk by UD.
Having said that, I have an abysmal fight prediction record. So BJ will probably win by KO in the first.
p.s. In case it's not clear, I am rooting for Sherk to win all the way.