Sorry but that is incorrect throwing off your back foot is incredibly wrong mechanics their is no disputing that and it's not up for interpretation. With that said it doesn't mean it can't be done or done successfully in certain situations. Some players develop different techniques of delivery with varying degrees of success. To practice this or devote time to this is pretty feeble in my opinion but all the power to Goff or any of his coaches if they think this is going to up his game to the next level.
