This is one of those fights where there are a lot of possibilies.
However, GSP, while being a great all around fighter has only one option to win this fight: Hold down a stronger, equally explosive (possibly more?) opponent, who has great JJ for 3 rounds.
No one in their right mind thinks GSP can stand with Silva. GSP's peppering style doesn't compare to Silva's technical power style. GSP could throw a thousand jabs and Silva wouldn't have to block more than a handful. To my knowledge only 4 MWs in the UFC have secured top position for any period of time. (correct the wrongness if it exists on that one, having trouble remembering that far back!)
There's little question that GSP could get the takedown. He's taken down WW wrestlers, why would his technique diminish assuming he moved up to MW, or to a catchweight, to fight Silva. The big question is can he secure and maintain top control? I believe its possible, given ample time to achieve the proper mass of a MW, he COULD secure and hold the top position.
Another area of concern is GSP's chin. Sonnen was taking Silva (an injured Silva at that) down at will, yet Silva still put him on his back with a beautifully timed elbow as Sonnen came in, which put him in top position over Sonnen. Serra KOed GSP with one punch followed by GnP. I defy anyone to prove Serra hits as hard as Anderson Silva. If Silva landed the same shot Serra did, or an equally powerful elbow/knee on an attacking GSP. It would be the end of the fight.
My opinion: Silva by KO/TKO. He has enough weapons to finish GSP. But I don't think it would be a shutout and if GSP actually came in a legit MW, I could be as wrong as wrong can be.
Sig courtesy of that photo-matic magician limba
I went out the way that I fight. I went out on my shield. Thatís it. Done. --Chuck Liddell
My goal is to end my opponent --Carlos Condit