Two MMA grappling specialists (with a notable late-career common opponent in Ben Askren) duking it out is something I've always wanted to see. I suspect Maia would have a leg up due to size, experience against more elite competition, and greater willingness to adopt skills outside of his comfort zone (boxing, offensive wrestling, etc.) -- but I want to see the opinion of others on the matter in a few different scenarios: 1.) Prime versions of each fighter in a ring enclosure under PRIDE rules. Three rounds. Fight takes place at 83 kg (183 pounds). 2.) Current versions of each fighter in a cage under Unified Rules (or, if you all would prefer it, you can discuss ONE-style rules instead). Five five-minute rounds. Fight takes place at 170 pounds (or 185 if we're going with ONE rules). 3.) No-gi submission grappling match. ADCC rules @ -76.9 kg (169.5 pounds). 4.) Gi grappling match. IBJJF Adult Black Belt rules @ 82.3 kg (181 pounds). Bonus: replace Demian Maia with Gunnar Nelson.