When it comes to self defense, men have a variety of martial arts to turn to because men, in general, have more muscle mass and are bigger. But for women, there is only one martial art worth learning (first) for self defense purposes. That is brazilian jiu jitsu (BJJ).
No other martial art will give as big of a return ratio in terms of time spent learning to real-life effectiveness. That is, other martial arts are also effective, but will take longer to get to the same level of effectiveness in jiu jitsu when it comes to saving your life in a real-world confrontation.
So why is BJJ such a good martial art for womens' self defense? Here are the 3 reasons why.
1. The Size Of The Assailant Doesn't Matter (Much)
If the assailant does not train BJJ, then the size of the assailant is almost negligible after 1-2 years of consistently training. Jiu jitsu was made with the small person in mind. Helio Gracie, one of the fathers of modern BJJ, was himself quite small. So he designed the art to fit his purpose.
In the first year, you will learn how to fight when someone is on top of you and also how to maintain your position while you are on top. These are things that can be extremely useful when going against someone heavier than you. Because at the end of the day, you will most likely end up on the ground if you are getting attacked.
I have seen women with a couple of years of BJJ training absolutely destroy guys on the ground who are as much as 100 pounds heavier.
2. There Is No "Puncher's Chance" With Brazilian Jiu Jitsu
There's something called a "puncher's chance" in striking. That is, striking has an element of luck in it that anyone can get knocked out at anytime with a lucky punch (or kick). It is not always the most technically skilled person that wins the fight---this has been proven countless times in boxing, kickboxing, muay thai, and MMA events. Sometimes, the less skilled fighter wins with a lucky strike, be it a punch of a kick.
When it comes to grappling, luck is taken out of the equation. Sometimes, you can make up for technique with strength. However, when you are against an assailant that has no grappling training, you can easily neutralize the strength of your opponent with some time spent training BJJ.
3. It Doesn't Take Strength To Render An Assailant Unconscious (Or Subdue Them)
The one really great thing about BJJ is that you can render someone unconscious, break a limb, or subdue someone no matter how small or "weak" you are.
With striking, you need a certain amount of force in order to render someone unconscious or knock them down. The formula for the amount of applied force is mass multiplied by acceleration. Thus, how much big you are (mass) is a variable when it comes to the amount of force you can apply on an assailant.
Even with other grappling arts (such as wrestling or judo), there is a lot of strength required. If you have ever tried to take someone down, you will know that a certain amount of explosive force is required to succeed. But with BJJ, strength is rarely the determining factor if an experienced practitioner is going against someone without any grappling experience. People without BJJ experience will not know how to defend against submissions or use their body weight to keep someone on the ground. That is, you can easily get yourself in a position to apply a submission to end the assault very quickly.
In this video below, you can see the girl has some BJJ experience handle guys without grappling experience fairly easily, submitting them over and over again. As soon as the fight got to the ground, it was pretty much over for the guys.
So if you are a woman and want to learn a martial art, pick jiu jitsu, and don't take those bullsh*t self defense seminars or classes that teach you to "techniques" you can use in just a few hours. Learning how to defend yourself takes time and some know-how.