In such a close fight I think home advantage will be the deciding factor. Carl may be able to absorb an all out war better at this stage of their careers so I think he will nick it and set up a 3rd fight.
If they have adecider it should be at a neutral venue and again its a toss up. If I hads to lean 1 way though Id go with Kessler. He seems to have that extra power and doest wait after exchanges like Carl sometimes does.
Great warriors and deserve the big payday