I have studied Jiu Jitsu, Karate and Kick Boxing (with Elbows and Knees), the one you would use in a street fight would be the kickboxing. It trains you to be no holds barred and to attack. Karate is garbage, Jiu jitsu is only good when you are tied up with someone, then you can throw them into some form of joint lock of choke hold. But most fights start out by facing each other apart from one another. I have been doing it for 12 years and kick boxing has never failed me once. You learn not defense but offense.