I think Jacobs will win an early round or a couple even, but Golovkin eventually finds his offense/range/wins the stamina battle and hurts Jacobs in the middle of the fight, able to end it. I think it ends with Jacobs having done better than most think he will.
Well since Jacobs is officially over 170 pounds, we will finally see Golovkin fight a light-heavy weight, unofficially. I say it goes 12 rounds. I won't bet on that but I feel it for some reason.