One thing that can separate a novice from a master in any encounter is knowledge of the pressure points. In traditional oriental medicine, there are 12 main meridians of pressure points that run along the human body. These meridians each have a time of the day where they are the most active.
AM Meridian most active during this time
1 -3:00 Liver
3 -5:00 Lung
5 -7:00 Large Intestine or Colon
7 -9:00 Stomach
9 -11:00 Spleen/Pancreas
11-1PM Heart
PM
1 -3:00 Small Intestine
3 -5:00 Bladder
5 -7:00 Kidney
7 -9:00 Pericardium
9-11:00 Triple Heater
11-1AM Gallbladder
Meridians can also be classified by whether they are mostly of Yin energy, or mostly of Yang energy.
Yin:
Lung (LU)
Spleen (SP)
Heart (HT)
Kidneys (KI)
Pericardium (PC)
Liver (LV)
Yang:
Large Intestine (LI)
Stomach (ST)
Small Intestine (SI)
Bladder (BL)
Triple Heater (TH)
Gall Bladder (GB)
Knowledge of these meridian channels and the direction of energy is vital in knowing which way to strike a pressure point. The direction of pressure used in acupuncture is opposite from the direction used in martial arts because in acupuncture the object is to heal and not to hurt. Remember when using pressure points, the goal is not to show off, but to use them effectively and only when you know how to use them safely.