Over the short amount of time I have been around weightlifting, I’ve heard many great arguments from many great coaches both in favor of and against working different positions from boxes and from the hang for the benefit of weightlifting. Many coaches on the side of the full lifts only would say that nothing mimics and benefits a weightlifter to lift heavy and lift properly like the full lift. Many coaches who I admire and respect state that partial lifts mess up much of the timing of the full lifts and in so doing prevent good lifters from lifting the same every time they touch the bar. These coaches would argue that lifting from the ground for singles, doubles, and triples creates the best chance for a weightlifter to create good movement patterns and perfect timing in the lifts. Their argument, which carries some weight, is that working lifts from the boxes or different complexes ultimately will hurt a lifter’s ability to duplicate proper movement under heavy load from the floor.
On the other side of the fence there are many coaches, including the USAW coaching course teachers, that would argue for the benefit of training each position separately. Many of these coaches, who have been instrumental in my own personal development, argue that training from these position helps the body understand exactly where they should be at each point during the lift and allows lifters to train the weaker parts of their lifts more specifically. For instance if you struggle with keeping the bar close and engaging your hips to full extension the training the snatch from a power position off the blocks would translate in theory to the full lifts. These coaches make a great point especially for the benefit of teaching lifters who don’t know exactly where the bar should be at certain times. The lifters don’t know or understand where the bar should be during the lifts and therefore are unable to hit those positions from the floor. The basic idea from is that if you don’t know where the bar has to be during each and every part of the lift then there’s less capability on the part of the lifter to hit those positions properly through the full lift.
Ironically, the coaches who argue for the benefit of position work also argue for the benefit of the full lifts. I have never met a coach who would argue against doing full lifts and doing them often. However I have met plenty of coaches who would argue against doing partial lifts and argue for only doing the full lifts. I find myself siding with those who believe there’s a healthy medium. I certainly believe that working from the blocks or working from different positions for the purpose of developing weaknesses is beneficial. However sacrificing too much of my full lifts from the floor in order to work partial movements is detrimental to my training in the same way that never working my weaknesses would be. The partial movements are beneficial but they must be used always in conjunction with full movements in a well drawn out program. I believe the full movements are the best way to train the lifts. However, accessory and other position work can be used properly inside of the training cycle if the full lifts are given their due.
Bottom line: use them both but make sure that one does not hinder the other And if you don’t know what to do then just do the full movement.