Centerline Advantage—To defend against a hand attack in the proper Wing Chun manner—that is, by using Angle Structure to overcome greater force—the student must instinctively combine some aspects of the Centerline Theory and apply them instinctively with proper technique, power, and timing in one smooth motion supported by the appropriate footwork to create optimum Centerline Advantage. For example, when an opponent launches a punch that the Wing Chun fighter perceives as a horizontal pyramid, the Wing Chun fighter quickly and instinctively “sizes up” the situation and recognizes the punch’s pyramid structure. He processes that information while projecting the Defense Pyramid he believes is most appropriate for the position. Because the Wing Chun practitioner is always aware of the Centerline, he already knows where to direct his defense hand’s energy: to a point between the tip of the Attack Pyramid and the Centerline. By doing so, he combines the concept of the deflective reaction of two colliding pyramids with awareness of the Centerline Plane, which tells him which direction to guide that deflection.
The term “Centerline Advantage” is defined as having the tip of your Defense or Attack Pyramid between the end of your opponent’s pyramid and the Centerline. To defeat an attack structurally, the defender must wedge the tip of the appropriate Defense Pyramid between two points: the end of the opponent’s Attack Pyramid and the Centerline. This method requires the least amount of muscular strength, relying instead on the Cutting Angle and deflective power of the pyramid to achieve the winning position geometrically. Whoever can get the tip of their Attack or Defense Pyramid between the appropriate coordinates wins. Suppose your pyramid is pointing down and in. In that case, it will point up and out, giving you Centerline Advantage if the tip of your pyramid also points down and in. This Centerline Advantage position is also known as “Inside Centerline.” However, it does not necessarily mean that the defender’s hand is inside the attacker’s hand, only that the defender “has the line”—that is, he has his hand between the opponent’s technique and the Centerline.
Changing the Line- Physically moving a mighty attack pyramid off the Centerline as quickly as in the Chee Don Sau example is not always possible. When an attack is so powerful that the Defense Pyramid cannot move it off the line, it is necessary to take other precautions to avoid being hit. Suppose the Attack Pyramid cannot be moved off the Centerline. In that case, the Centerline can quickly move away from the attack. Consider the Attack Pyramid and the Centerline, which must be manipulated in proper Wing Chun defense. Suppose the defense hand is placed on the attack hand but cannot move that hand away from the Centerline. In that case, the defender has the option of shifting the position of the Centerline itself rather than attempting to move the attack away from its intended path. All he has to do is change the endpoint of his side of the Centerline Plane by moving his own Motherline. He has moved to a position where his own Defense Pyramid now falls between the tip of the Attack Pyramid and the new line created by his stance movement, resulting in the same Inside Centerline relationship as if he had been able to move the Attack Pyramid off the line.
To summarize, if an attacker attempts to punch you in the nose and you cannot move the punch, move your nose! This can be accomplished by any Moving Stance that changes the line, thereby supporting the defense hand by improving Angle Structure, increasing power, and possibly improving the Angle of Facing. The important thing is that the line is moved in the right direction to gain Inside Centerline as quickly and cheaply as possible.