1. 

An umbrella makes an excellent weapon but keep in mind the key is not just blindly wailing away as the umbrella will break too. There are really good targets you can hit that don't need a lot of force but that will probably end a fight. I would not use it to perry. Rather move your feet and then hit the hand holding the blade as hard as you can. If you break your opponents finger(s) all the better but just hitting a joint so your opponent can not close his hand again will make it so they can not hold on to the knife. If you break your umbrella break it by hitting not just blocking as once you finish the block it's 50/50 again and you will have to do something else and if you broke your umbrella just with the block you will have lost your weapon. I would use it to poke. It's stronger to poke with than to hit, not to mention pokes are faster and harder to detect for an opponent than a strike.

BTW they are great against dogs too. Ever opened up an umbrella at a charging dog? I did and the result surprised even me. The dog turned and ran away japing you would have thought I beat the crap out of it and I didn't even touch it.

a weapon is only as good as the person handling it. understanding the weapons strengths and weakness goes a long way. most umbrellas are fairly weak even as a thrusting weapon they will just collaps. there are a few that are relatively strong enough for this, but if thats all you have its better then nothign at times

I'm wondering what the argument for and against this practice would be. I'm thinking of a golf umbrella(the big umbrellas that can usually fit 1.5 person) for this purpose. I can't use my fencing training in this because the side and the tip of the umbrella isn't going to do much damage against a person. Rather I was thinking of using it like a bayonet but deliver blunt damage rather than puncturing damage, and use it to parry against a blade if such situation rises. Let me know your thoughts and arguments. Thank you.