Both fighters are two of my favorites. I think a case could be made for either of them winning. I agree with a lot of things previous posters mentioned. The first thing most people think of is Reem's chin, understandably. Against JDS this would certainly be the biggest factor, as JDS has always had that dynamite one-punch in nearly all his fights I've watched. Also, Reem seems to have fought much smarter since changing camps, while JDS gameplans (or lack of following them) seems to get worse each fight, and his chin seems to finally be on the verge of letting him down. Overeem would be another big test for JDS's magical ability to recover. I would lean toward JDS, but so many things can happen. JDS always fights the same way, circling while backing into the cage always looking for the overhand right. It seems like every fighter that puts their back on the cage vs. Overeem ends up taking a barrage of punches and knees and ends up on the mat or in serious trouble. Very exciting fight where I'm sure there would be lots of fireworks.