Years back a college kid filmed my arrows. I do not have a copy. I was surprised to see with my heavy longbows, not at all center shot, that the initial inward bend was virtually the same when shooting with fingers versus shooting with a mechanical release with wrist strap and the little jaws. At the time I was more surprised how loud a clank those wrist strapped mechanical releases were a 90 pound bow. With my plungered past center shot target bows there was still some initial bend, but the mechanical release showed much less than fingers. The other one that baffled me was that a longbow can shoot a much higher spine arrow by hand than with a shooting machine. That little bit of palm sided give can work wonders, but it needs to be consistent to give a predictable outcome. I got a kick using the shooting machine with the target bows, shooting tight groups at long ranges, when you could actually see the affect of a variable side breeze on the accuracy, not as much as one would think.