It's all part of heiho, strategy, to overcome your opponent before the fight begins. After the bow, a unexpected quick flash to the eyes with a momentarily locked gaze will hopefully unsettle the opponent. It is here, in this split second, that the outcome is determined. However, the bow is always respectful and heart-felt. I believe never be dishonest with a bow. This way even the slightest acknowledgment has great meaning. Sometimes I think bowing is an art, not unlike cha-no-ryu (tea ceremony). It has to be practiced with your soul to understand its meaning. My sentiments exactly. Much like a punch, as many times as I have bowed I never seem to feel I have "mastered" it.