I'm fairly new to pizza; I've probably only made the master dough (without starter) three or four times. I am following measurements and steps to the letter, but when it comes time to ball the dough after the 24 hour bulk ferment I struggle to get a really smooth skin on the dough balls.
See the photo below (or here for hi-res: https://imgur.com/a/lq3vJfU) for an example. The skin splits a little bit and no matter how long I ball for (not too long, I'm scared of over-kneading), I can't get the balls perfectly smooth.
Where am I going wrong?
EDIT (4/24/19): Might be important to add that I'm mixing my dough in a KitchenAid with a c-hook. Tony writes that the dough should be mixed on the lowest setting so I mixed on "Stir" (2 is the next highest setting). In videos where he's teaching this method, Tony seems to use this speed as well. Wondering if I should be mixing on 2 -- the higher speed might be acceptable given the short mix time.