Just because we study Jiu Jitsu, we are invincible – false!!! wrong!!!!!! What we have is a false sense of security. There are a lot of tough people walking around that can do a lot of harm.. . It is not about winning, it’s about surviving.
Don’t engage in give and take fighting. Sporting events encourages this for entertainment. Stay out of range. Frustrate the aggressor who wants the give and take fighting..
Wait for the attacker to come. as they step in, crash in or step out of range. Arms length fist to fist distance.
BJJ self-defense against a boxer is crashing in. Defense is not with the arms and legs, blocking, it’s with the feet. One foot back or one foot forward. To be able to move quickly, be on the balls of the feet. Be able to move back and forth with ease. Move in 90 degree angles. Strong leg 1st. Practice this. Ready to use the side kick.. If you are doing a mirror image of the attacker, always step wide then adjust. Arms close. See through hands. Chin down. shoulder slightly turned, and Don’t shrug when chin is done..
Decide right now, if you need to fight, you will. Stay out of trouble even if a person says something stupid. When the line is crossed, defend. Don’t debate in the moment. Don’t try to figure it all out while under attack.
journeyjjbluebelt 
I think your post means well but it’s misguided. Real violence doesn’t happen at ranges of fist to fist. It happen up close, fast and hard, and when you don’t expect it. You are talking about a category of social violence, specifically called a “monkey dance.” Which is your typical alpha male, I push you, you push me, looping overhand. This is easily avoided by checking your ego or simply leaving. If I have time to create space or range, I might as well leave.
I agree. Most assaults are surprise attacks. I believe up to 60%. Your right this post is dealing with the monkey dance. I assume the attacked is not permitted to leave and there is an escalation to a fight. Thank you for your comment.
Jason, thank you for the clarification.