Should my knuckle be facing the ceiling? Or not.knuckles
Yes. It puts your wrist directly under the bar instead of being torqued backward.
You wouldnt punch some one in the face with a limped back wrist would you?
Pretty much this. Watch youtube videos of backyard fights for proof, the guys with a limp wrist and a bitch slap punch get beat, the guy coming in straight at your face wins.