Sensei Malcom Dorfman, 9th Dan, explains the three point of Power (San Ten Riki Ho) in a fight. Escpecially the difference between sport karate and street fighting differences. Also the points to survive a fight, where no refree or sport rules will help you at all.
Watch here the impressive competition kumite fights of sensei Frank Brennan. He is a complete fighter with hands and legs in any situation and a renowend karate fighter of the United Kingdom. As you can see those bouts were really hard for both sides.