nicolas pettas said in an interview how difficult it was for him to grasp the concept of being "touched" in his face. Something about being touched in the face is a discrace is KK (or something like that).
"in karate you can't punch to the face, and you ofcourse the bareknuckle karete... In the 15~16 i can remember the times ihave been kicked in the head.. In boxing the first thing they teach you is to punch you to the face.."
YouTube - Fight Japan: The Smiling Assassin Segment Nicholas Pettas
Before getting into K-1, Pettas fought in high level Kyokushin tournaments, so he would obviously be very conditioned to Kyokushin rules, and under those it would obviously be a big disgrace to break such a rule since it would show lack of restraint etc.
But there isn't some general taboo in Kyokushin against touching the face, Originally Kyokushin
did allow bare knuckle face punches. I've read some interviews with various legendary karateka, Jon Bluming for example, and they all describe the training at Honbu in the early days as extremely gruelling with the ambulance picking people up a couple of times a week. You can see that in old videos too, I particularly remember one of Mas fighting some of his students, knocking them down with face punches.
But it is true that it will pose a problem if you're completely tuned to Kyokushin rules, I will quote Shihan Howard Collins, 7th dan under Mas Oyama:
"Today more and more dojos are basing their regular training on competition training and ignoring other aspects of Kyokushin training. Remember that competition is not Kumite! There are rules and regulations limiting your technique, which is good, as we need to protect the competitors. I competed for many years but I always remembered that it was a game for a day."
This is what I mean when I say that a Kyokushin fighter who can't take punches has a problem with the focus of his training and it is not a flaw in the art itself. I can draw a parallel to Judo, which also has techniques that are not allowed in competition, like joint locks. A Judo fighter who only focuses on techniques allowed in Judo competition would cripple himself against a BJJ practicioner or Sambo fighter, but as with Kyokushin the problem is in the training and not the art since all the techniques are there.
Further on, I have never seen anyone question the ability of someone who comes from a grappling art without strikes to take a punch to the head or defend against it, despite them obviously having even less experience of head contact, especially considering that Kyokushin guys certainly aren't aliens to taking kicks and knees to the head and face. Now you say "Well they obviously learned that when they picked up MMA training". And to that I say "So does the Kyokushin guys".
Last but not least, Francisco Filho, Glaube Feitosa, Sam Greco, Semmy Schilt, Bas Rutten, Andy Hug - all fighters with a strong Kyokushin background who seemingly have had no problem adapting to kickboxing or MMA rules. Before anyone says "Well, Bas Rutten only did Kyokushin for a while before he started doing Muay Thai" I'd like to point out that he's a 5th dan black belt and credits Kyokushin as the foundation for his kicking on one of his DVDs (sorry, can't remember which one). A 5th dan in Kyokushin takes many years, and most people never progress above 3rd dan - Rutten obviously continued doing Kyokushin even after he started Muay Thai as well.
