well, Saban has been looking at many free agents, but the thing that wasn't mentioned is that he only looks at those who don't command a premium price-tag. There's a reason some guys are free agents, and a reason they come cheaply. I don't know what the success rate is, but I wouldn't think that it would be much more than 30%. Just about every offensive lineman has been a disaster (although Shelton might stick as a guard), but I have to give him credit for many of the defensive players.
His philosophy is to build through the draft, not through free agency. That sort of approach takes years