Also just reading through again and looking at where your skin is ripping. V odd...you are not throwing correctly and your fist is all wrong at the point of impact. You should be connecting with the first two knuckles of your fist first then the rest of the fist follows through on impact. Looks to be like you are doing more of a closed fist slap if thats where your skin is ripping.

take some lessons or switch to open hand.