The reason why Khan will beat Barrera.

SPEED.

Speed kills. Look at Mosely v Margarito...nobody on god's earth gave Mosely a chance.

Good thing for Khan is he has power too. Barrera at his age won't be able to handle Khan devastating speed. That's all there is too it. Sure Khan has a dodgy chin. But you have to land to inflict damage. That's another problem. I just don't see Barrera landing at all, Khan's reflexes are too fast.

Khan TKO around 5.