I follow Nathan closely. And he himself has espoused the cause of backspin. Here is where it gets lost in translation. Just like there is an optimum launch angle there is also optimum backspin. For example if you pop up that has crazy backspin but its not going anywhere. So the chart showing massive backspin probably takes some shallower fly balls into consideration. There is no doubt you want backspin but all that really means is you struck the ball at the correct spot. Hitting 'top half' will result in top spin ground balls. Don't focus on backspin, focus on hitting just below center of ball with a 10 to 20 degree uppercut. And golf I think what he means about getting hands down is to drive them down while barrel is still up and then once in strikezone bat starts to make its swing path. There is no correlation between this movement and the chopping motion.