The guard
Typically, the guard is considered a defensive or preparatory stance. The French musketeers used an “en garde” (on guard) call as warning and courtesy to the opponent to be prepared, or on guard for the fight.
The guard is defensive and offensive.
Although the guard has a defensive role, it is prone to fail if does not contain offensive elements. The most efficient guard is the offensive one.
The guard is the evolution catalyst in jiu jitsu.
The guard is a fundamental element spurring the evolution of jiu-jitsu. Part of the art is perfecting old-school guards. Another part is creating new school guards, which spawns new passes, transitions, and submissions.
The guard is an anchor and pathway.
The guard is the most influential element in jiu-jitsu. The guard anchors the structure of the fight and creates a path to a sweep or submission. By anchoring, a guard stabilizes and stops the attack of an opponent.
The guard is only attack.
Jiu-jitsu and judo newaza has two categories of guards: closed and open guards. The closed guards (e.g. full, half) tend to be more defensive in nature but can facilitate attacks. Open guards are more offensive in nature. Ultimately, the nature of guard is determined by the mind-set of the user. The guard itself is an attack and should always threaten sweeps or submissions.
Lede art by Gartista.