People often turn to the martial arts to learn how to defend themselves. The trouble is that the 'martial arts' is about as vague as saying 'sport' or 'vehicles' when it comes to what is 'good' or not.
If I want to drive a car fast around a racetrack then a family SUV is not ideal. However, an SUV is capable of going off road a little but won't be as good as a more off-road orientated vehicles such as a Jeep or Land Rover.
The 'Martial Arts' is a wonderfully broad and diverse collection systems, styles and organizations. My blogs are going to focus primarily on real world application of fighting skills in a self defense situation. As such more esoteric styles such as Kendo have very little practical application for self-defense, However it is the case that anyone well versed in Kendo, if they get their hands on a stick of any length will fare far better than the average person in a street fight so ALL systems have their value to a greater of lesser extent!