We learned to pull back our fist on the side, directly under the arm after a strike. However, today when you pull back after a strike, you bring your fist back to your hip (the lower side of your abdomen). This never works during an actual fight. I believe that the proper technique is to put power and strength into pulling back your fist. Today this looks to me very strange, to put so much power into striking with your fist. I would use only 80% of power when I extend a strike with my fist, but 100% of power when I pull it back.Motobu Choki
It seems like Jion illustrates the old standard way of using tsuki.