"With that big a crowd, the best you can hope for from a weapon is intimidation. Something that'll stop them and make them back down for a few seconds while you quickly leave. I don't think a switchblade would do the…"
"Most switchblades are not very useful - blade wise. The very good ones are very expensive, and finicky to unreliable at best. A fixed blade (even a small one) is better in a fight. But no knife is going to turn the odds when that overmatched. "