To me it is psychological, I shot for years open handed without one and never dropped my bow once, but there were times where my groups would always have one or two arrows an inch or two to the right, when I got my new bow, it came with a wrist strap and I figured what the heck it can' t hurt, I put it on adjusted really loose, to be honest there is no tension at all on the strap when I am at full draw, I no longer get the mixed groups.