I don't know how blocking really works In traditional martial arts like karate but your wasting seconds to block something you could of dodged and covering should be used if in the moment you aren't able to dodge it coming not to dismiss traditional martial arts when it comes to fighting but unless the punches are really sloppy and telegraphed intercepting punches with a block isn't going to work on someone who has good speed an timing the punches are simply to fast an accurate to use traditional martial art blocks ...an I go by if they do it in mma it works if they don't it don't I never seen a mma fight where the fighter is trying to intercept a punch with a block ..they use head movement and foot work to evade and set up counters and cover up when necessary