What people don't understand is what a technical boxer JDS is. He is the only guy not only in the HW division but in all of MMA to have professional level boxing. He could go toe to toe against a professional heavyweight boxer in a pure boxing match. He might lose, but he wouldn't be embarassed like pretty much every MMA fighter would. He also has excellent foot movement and clinching skills, which means that Overeem will have a hard time using his kness against him.
People who think that Overeem will walk all over JDS are delusional and here is why: this is boxer vs kickboxer, and a great boxer beats a great kickboxer 9 out of 10 times. Why? Because humans cannot use their legs and knees as effectively to strike as the fists. We don't use our legs to touch and handle things for a reason. We have much better dexterity with our arms than with our legs. The only people who can use their legs for fighting with any effectiveness at all are extremely athletic guys like Anderson Silva and Jon Jones, and Overeem simply doesen't do with his legs the crazy things Anderson and Jones do.
My prediction: JDS will evade Overeem's clinch with his excellent foot movement, and use that same excellent movement to pick Overeem apart in the stand-up, jumping out from his kicks and finding openings in Overeem's guard and connect. Overeem will either get KOd or TKOd.
SUCKMYMUSCLE
You must be new to mma or have a mild case of down syndrome. A professional kickboxer will destroy a boxer every time. In terms of striking, Boxing is first, then Kickboxing, and mma is at the bottom. Alistair isn't the best technical striker, but better than any other other heavyweight, though we have to wait for the JDS fight to see who comes on top.
I don't know if you've watched any K-1, but there have been pro boxers in K-1 and they haven't faired very well. When they start getting kicked everything changes. The cute little footwork goes to shit after a couple of proper K-1, Bonjasky-style mule kicks to the thighs. Nevermind a head kick. I've seen JDS make a lot of mistakes leaving himself open in standup exchanges. Overeem, needless to say, is stronger and probably hits as hard as Carwin, if not harder seeing as he is more techical.
Regardless of what happens, this is going to be a hell of a fight. Junior probably has a better chin than Overeem since he's never been k'od, but Overeem has the power advantage. If in doubt, while JDS couldn't knock out Big Country, Overeem put down Ben Edwards (look it up to know what this is a valid comparison) three times from three punches in one round.
