I think Darrin Walls should win the competition for the #2 CB and here is why:
1) Walls is younger and has better upside.
2) Walls is 6 feet tall and Dimitri Patterson is 5' 10''
Size isn't everything. But as outside receivers are getting bigger and bigger each year, it is becoming more of an advantage to have taller corners on the outside.
3) Dimitri Patterson played his whole career in the slot as opposed to Walls who is primarily an outside corner
Patterson performed well in the slot for Miami last year, but we don't know how he will hold up on the outside. Asking a 30 year old to change positions is not ideal. Walls on the other hand has spent his whole career playing on the outside. When his number was called on last year, he performed well.
4) Patterson is slow
Sometimes its OK to have a 5' 10'' corner on the outside if that corner has speed to make up for it. Patterson ran a 4.60 at his pro day which is below average (remember that he posted that below average number when he was a 22 year old and is probably even slower by now). Walls on the other hand ran a 4.43 at the combine.
5) Patterson is coming off groin surgery
6) Patterson was cut/released by six different teams throughout his 8 year career
He never started on the outside for any of the six teams. If these six teams didn't think he can get the job done as an outside corner then what makes us think he can at this stage in his career. Walls was only released by the Falcons with an injury settlement.
I was really surprised when Rex said he views Patterson as the favorite for the #2 corner spot. To be clear, I don't think the Patterson signing was a waste. I think he can be effective in the slot as he has great instincts and experience at that position. But if he is the week one starter at the outside, then he will be a major weakness in our secondary. I think Dowling or even McDougle (he is the same height as Patterson but at least he has good speed) are better suited to battle Walls on the outside, not Patterson.