Thanks for the reply jwt. I was asking because, just like with all striking, there is good and there is not so good or bad technique. I see a lot of back fists actually hitting as back of hand strikes, and these tend to not be good. Being hit with a good back FIST technique is a ton more effective then being hit with a back hand. The key is applying the most force to the smallest area. I've been hit with a back fist to the point just below the ear along the jaw line, at the same time this was a compound strike with the forearm coming in under my chin and across my Carotid artery. I started to see "stars", my legs got weak, and THEN I felt the pain from the hit. I went down to one knee and took an 8 count to recover (this would not have worked in MMA but that day it did because of the rules!!!). The stars went away, but the pain was there for several minutes. I did not get knocked out lucky for me, but the next punch would have floored me. Later I was shown what hit me. The thing about this is that the hit was good, but then I was shown an open handed version of it by the same person where instead of the back fist, it was more like a back slap with the knuckles hitting... and it was just as good if not better, and it only took half the distance to hit effectively. Goes to show that even something good, might have something even better as a variation.