My goal in teaching a martial arts class is that, when the students walk out the front door after class, they will be better prepared to defend themselves than when they walked in for class, this includes the very first class they attended. Intricate, complicated, and unnatural movements, exotic techniques, and weapons that are useless in modern society, may be a part of the art of a martial art (and Taekwondo has its share of them), but, they should not be confused with the martial part of a martial art. Taekwondo primarily uses hard block but when it comes to sparring, good fighters do not use hard or soft blocks, they evade or use the forearms in a tight guard to block attacks that were not avoided; hand and foot attacks are coming to fast to block. My chosen martial art is Taekwondo so I teach the art of Taekwondo, however, no matter its source, be it from Chinese Gung-fu or Icelandic Glima, if a martial technique floats, I teach it.
When I throw vertical punches into the water, they sink.
In Taekwondo, and most other martial arts, such as Shotokan, Shorin-ryu, and Goju-ryu, the fist rotates (twists) during a punch. However, a few martial arts styles, such as Isshin-ryu and some kung-fu styles, do not use the twist; their fist stays vertical during the punch and the thumb rests atop the fist rather than folding underneath.
Each camp has explanations as to why their method is stronger, faster, and better. My argument in punching is to look at natural movements and to look to those whose livelihood depends on the speed, power, and effectiveness of their punches—professional boxers. Boxers fold the thumb underneath and they twist their punches. It is a natural way to make a fist and a natural way to punch.