In almost all "martial" schools of training, one of the most important aspects of a good defense is protecting the zone.
The zone in this reference represents the main parts of the body. From just below the groin to the temples of the head and between the shoulders are the major sensitive points of the body and the vital organs, which if injured can cause the most damage. For instance, one of the most effective attacks against a male or female attacker (and one of the attacks almost always not allowed in any competitive sparring or fighting) is to hit the groin. Being hit in the midsection when unprepared can take the wind out of even the strongest of people. And one well targeted strike to the temple will case someone to black out immediately. There are many other points of interest that lie between the groin and the temple which can cause a great deal of damage.
However, this is for a discussion another time. Let us return to our focus of protecting this very valuable zone. In almost any combative, or “martial”, activity, you will find examples of how they protect the zone. In boxing, the fighter holds hit guard with fists close to the chin and elbows tucked into the body. In fencing, the body is turned to the side to present the smallest target to the vital zones as possible.
In Martial Arts, protecting the zone also exists and can be found in any style. One of the first things most students learn is to keep their arms up to guard for sparring. Repetitious punching drills focus not only on delivering the blow but also returning the arm and hands to a guarding position. Many kicks chamber in such a manner that they serve dual purpose of both protecting from and preparing to attack.
Protecting the zone, however, goes beyond these "resting" positions. To be an effective Martial Artist, one must also be able to project, much like aiming for a collision in the game of pool. The most efficient blocks require very little movement to execute and use this type of projection to mitigate the danger.
So let’s break this concept down a bit. First of all, doing any blocking that extends beyond the zoned area is excessive. So that means if your final “block” movements extend beyond the shoulders or above the temple and below the groin, you’ve wasted energy in performing that move.
To further enhance blocking, consider at what point of the attack you deflect. The need for accuracy in your defense increases the closer the attack is to your body before you block it. Most often, you need to catch the front of the attack in order to deflect it effectively. Blocking the attack further down the arm results in reduced deflection and a definite hit to the body. However, the closeness of the block keeps the zone better protected as the body's position is still tight like a boxer.
Conversely, one can deflect an attack further away from the body. There is far more room for error and the defense can become an offense if you are able to hit softer points of the body. For instance, if you catch an incoming punch on the forearm or just before the elbow before the attacker tenses, you can cause them damage and pain as they attack you. You may not have to move as much for this type of deflection as minimal changes make large differences in the projection of the attack at the end. However, deflecting too far out from the body compromises your position and exposes the zone to other potential attacks.
A happy medium is normally with the arms roughly at 120- to 90-degree angles and held in front of the body. This is far enough away from the body to allow for a comfortable reaction time, but not so far away that your defense is compromised.