Rahman is obviously the more accomplished fighter. However, he is clearly faded and way past his prime. Maybe not shot, but definitely not where he used to be. Arreola is young and still has decent reflexes and skills when he wants to use them. My guess is that Arreola and Rahman put on a fun fight for five or six rounds, but Cris starts to break him down and begins dominating after that fun first half. Arreola wins by 9th or 10th round TKO. The Rahman of 4 or 5 years ago might have been able to beat Arreola. Then again, that Rahman was beaten solidly by Ruiz, Maskaev, and a past-his-prime Holyfield. So, who knows?