Combat sports tend to use quite a different guard to those practicing self protection. There are many variations of “The Fence” which is used for self protection. However, in the most basic form of The Fence (arms forward between the aggressor and defender, palms open and usually facing downwards) it can be very similar to the fighting guard used in many traditional martial arts and to the guard used by the Victorian Bare Knuckle Boxers. The main difference being whether the hands are open or closed, but the arms are in very similar positions. Furthermore, traditional martial arts were developed for self protection rather than sport and although Bare Knuckle Boxing is technically a sport, it is probably one of the closest combat sports to real life combat.
In the video below these images, we look at the different types of guard and the relative merits of these 2 different types of guard.
Karate Guard The Fence
Bare Knuckle Boxer Modern Combat Sport