When you have reached the top of the mountain in two different weight classes, it really shouldn't matter which weight class you compete in. For BJ Penn though, that might not be the case.
He has won both the UFC welterweight championship and lightweight championship. He has beaten some of the best fighters in the world. He has long been thought of as one of the best pound-for-pound fighters in the MMA world.
So why does it matter which weight class BJ Penn fights in?
Welterweight is the class that Penn has had most of his career struggles. Prior to 2010, he had lost five fights in his career, three in the welterweight division.
He has never beaten Georges St Pierre, easily the best welterweight fighter in the world.That should be Penn's motivation to remain a welterweight, at least for the foreseeable future.
BJ Penn has as much talent as anyone, but the desire to get over that GSP hump is something that has to eat at him. The two men have fought two times in the past. The first one was a close fight in which GSP got a decision victory. The second fight was not close at all. GSP took the fight to Penn and made him look like a rag doll before it was stopped after the fourth round.
As a lightweight, the only reason that BJ Penn would go back would be to avenge his two losses to Frankie Edgar. He doesn't have anything left to prove as a lightweight.
As a welterweight, Penn could get another chance at GSP. He wants to make a point to himself, to the world and to GSP that he is back with a vengeance. The biggest possible splash that BJ Penn could make would be to get a fight with GSP and take the welterweight title from him.
The only way that will happen is if Penn beats Jon Fitch in February, and GSP beats Josh Koscheck and Jake Shields.