Lockyer WAS the best full back in the world. Not the best 'player' in some general sense (which I'm not even sure means anything). The best full back. Easily the best attacking fullback of his era, and not too shabby in defence either.

As a stand off, I'd argue he was the best in the world for a year or so, but never as dominant as he was at fullback. His last two seasons saw him lose his pace, but not his ability to control the attack.