This is what I see. There's no way Machida will be the agressor in the beginning. He'll draw Jon Jones and wait for his flashy moves. There he'll figure out his timing and strike with pin point counters. The reach on JBJ will certainly play a role, but I think the later it goes the better Machida has in winning. JBJ is very young and will make a mistake eventually. He started to get tired in his first fight or so if I recall. Greg Jackson said that JBJ was flat out tired by the 2nd round, but still pushed on. That shows an adrenaline dump and lack of experience more or less. Look at GSP and Anderson Silva. They look exactly the same in the fifth round as they do in the 1st round more so with GSP. They conserve energy and are very, very well versed in fighting in a championship setting. It's just another walk in the park for them two.
So first three round goes to JBJ. If it goes to the 4th/5th then I'm betting on Machida.