The “basic centerline” is an imaginary line extending outward from the center of your chest and runs through your nose and navel area. It is a guideline for splitting the body in half. It splits the perimeters as a guideline to follow with your hands to minimize movement. Right hand in right side, left hand in left side. The centerline is for learning purposes to teach the right and left hands to work independent of each other. The centerline is an exercise line to understand efficiency in training and technique.
The “centerline concept” allows each hand to act independently of the other while keeping the body in such a position that you can touch your opponent with either hand at any time. There are two important reasons for the centerline concept existing. First, it allows both hands to touch the opponent at any time and it allows your own centerline to be on the opponent. Second, the centerline creates a power base for both hands to function in a strong manner. It creates a stable base and power flow. It allows you to be efficient with both hands.
It is important that the centerline concept becomes a feeling and part of your natural expression of technique. You want the concept to be a natural part of you. The centerline concept creates a powerful attack base to operate from. The centerline concept is important in trapping, and the power base, so you need to be sensitive to the opponent, relative to feel. The centerline concept allows for an upper torso power base to exist equally for both the right and left sides. It acts to keep the base solid and allows each arm to remain powerful. It makes it a strong base that is hard to disturb.
This is a simple concept, but one of the most important principles in DJKD and WCD applications. The efficiency of trapping and sticking hands (phon sao and chi sao) as well as the lin sil die dar (multiple attack theory) relies to a great extent on this one concept. To break the centerline, weakens the versatility of this theory. Using both hands independently of one another, yet having them work together as a team, allows for a much wider range of effective inside techniques. Since both hands can function offensively, defensively or both, this gives the opportunity to perform double hand techniques.
Initially, Chi sao is where this concept is the most important. It is the first stage of Trapping and sets the foundation for later Phon Sao techniques. Maintaining your centerline (keeping square to the opponent) gives you the opportunity to perform double hand techniques and this greatly restricts the opponent’s offensive potential.
The centerline is for a natural line of power that allows you to centralize and flow. It will really reduce down his capability where he will have to use more effort to set you off your base. Violating the centerline makes one side shorter and opens the gate to be attacked. Even a small floating of the centerline weakens this base. It can be floated but not more than 15 degrees. You can pivot further if you have control of the opponents energy.
Applied Centerline exercises in training Module One.