i don't think obi-wan was stronger, or even more powerful than anakin. I think anakin could defeat enemies that obi-wan couldn't defeat. However, i think in THEIR duels, anakin will lose to obi-wan. Obi-wan was the master, he taught anakin everything. He controlled their duel on Mustafar(by quotes i posted earlier in the thread, and i stand by as the most conclusive insight into their mindsets in that fight) , and he won, and i believe, circumstances repeated, with the ROTS anakin, since at that point, he didn't know anything Obi-wan hadn't taught him, Anakin couldn't beat Obi-wan. he might be stronger, but that doesn't automatically make him the winner. (look at Luke vs. the Rancor as proof of that.)