Knowing any martial art style would be helpful, to decide what form or style of is best for self-defense. Nevertheless, in real life situations where the attacker has a knife or a gun, I would say run, run as fast as you can. Krav Mata, Jujitsu, or Kung Fu cannot stop a bullet. You can spar with a partner with a knife, which can help some. But in a real street fight the techniques may not work because no two attackers will attack in the same way. Self-defense to me means getting yourself out of harm's way. In real life situations, you can train for years in any style of martial art, but when it is time for reality, you may forget what you were taught in a panic.

There are no simple answers. Every form or style has value. Having a little training would help in some situations. I would look into Jeet Kune Do for more of what to do in street situations. Jeet Kune Do is not a single form or style. It has techniques from other styles, changing it in ways to perfect it, making it unique and original to Jeet Kune Do. Bruce Lee founded Jeet Kune Do in 1967. Meaning, "Way of intercepting Fist." It is a hybrid fighting that is based upon using different "tools" for various situations. The situations get broken down into various ranges (Kicking, Trapping, Punching, and Grappling). Jeet Kune Do students train in each of these ranges equally. This range of training serves to differentiate Jeet Kun Do from other martial arts. Jeet Kune Do is unlike more martial arts that are traditional, Jeet Kune Do is not fixed or patterned, and it is referred to as a "style without style."

A premise that Bruce Lee used Jeet Kune Do was known as "combat realism". He said that martial arts techniques needed to be incorporated based on its effectiveness in real fight situations. It was this that would differentiate Jeet Kune Do from some other systems available that had an emphasis on "flowery technique". Bruce Lee claimed that "flowery techniques" would look really good but were not practical or they would prove ineffective in situations where it came to self defense or surviving on the street. Jeet Kune Do practitioners subscribe to the notion that the best defense is a strong offence.

To this day JKD is ever evolving with the new forms and styles. Many would beg to differ with Brazilian Jujitsu and the Gracie camp, what we see today in Mixed Martial Arts. At the same time, the MMA is more sport with rules confined in a cage. Not that there is anything wrong with MMA or the UFC but in real self-defense situations there is no time to roll around the ground trying to put someone in an arm bar or triangle. In real combat situations, there are no cages that you are confined in with nowhere to run. There are no refs to stop the fight when one person can no longer defend himself or herself. In real life situations, if no weapons are involved Jeet Kune Do training and techniques will help in real combat situation. If there were a weapon in play, if you are not Bruce Lee I would say run, run to the nearest police station. Do not stand in place trying to intimidate your attacker by breaking boards because "boards do not hit back."