I know it's been a while, but a fight in a bar or nightclub could get pretty wild, and you’d have to worry about the crowd, security, and getting kicked out. A backyard might be the best option if you're thinking about something more private. You’ve got the space, and it’s a little more laid-back than worrying about getting banned from a bar or nightclub. Plus, no random people are jumping in. It all depends on the vibe you want. If you’re talking about a more controlled setting, somewhere like a
gentlemen's club might be a good idea—they tend to have a lot of security and less chance of things getting out of hand.