I'm gonna repost this since I have seen some pretty nasty slice wounds on some oogles that were friends and should have just punched each other instead of escalating, but they rent confident in and to and so they cut eachother over BS. Listen to The guy who said don't pull it unless you are ready to cut someone. Your opponent might have just been taking shit and now he thinks he has to fight for his life. Thusly, you might want a couple small cheap, disposable & easily concealed knives are best. Brandishing it isn't how it is going to save you.If you are being attacked, you don't let them know you have it till you are already cutting them(not even then if you are fast), then escape and CLEAN THEM OFF & ditch them where they will never be found. DO NOT USE LETHAL FORCE AS FIRST RESORT IN STREET FIGHTING ONLY TO ESCAPE WITH YOUR LIFE IF NECESSARY. You may have to explain it to a judge so don't go cutting every drunk that tries to swing at you unless you are in real danger. Anything longer than four fingers is a spicy item likely to get you arrested & is overkill. IF the size of the knife really makes that much of a difference then you re not confident enough with knives and it will likely be taken and used against you, making concealment, speed and violence of action very important. The less proficient in violence you are the sneakier and quicker you must be, no time for threats or brandishing this is for sure.