He has never been tagged by a guy who he wants to put on the floor.
GSP is very smart. He won't try to mix it up with Silva like he did with Condit.
Rashad had a good point about fighters on top of Silva advancing in position. GSP has some of the best guard passing ability in the game. I really think once gets Silva down he can seriously threaten him.
What happens if Silva stops the take downs? What if Silva starts the fight with his hands down or comes out swing from the start? Everything on paper says this fight should be competitive and a slight edge to GSP based on Silva's pass. However if this fight happens I do believe Silva will murder GSP. Remember it's Anderson Silva who is asking for this fight, he is already the goat of MMA. Now you combine with what he can do in there and the fact that he has called out GSP...means he knows he can win this fight.
He is 16-0, you take away the first chael fight he has looked virtually unbeatable. 11 victories via ko/tko all 11 he has made it look easy. When GSP gets hit he panics, anderson silva is one of the best strikers off his back, never mind his bjj, GSP will be in danger for 25 mins with the best in the business. He is not going to hold silva down, because eventually silva will fight back unlike any of his opponents who GSP breaks mentally during the fight.