I don’t think I’ve ever been in a real conversation about the use of martial arts for self-defense without someone adding a stipulation about “but against an untrained attacker…”. One of the assumptions I’ve encountered a lot relative to the use of martial arts for self defense is that of the surprise attack by some random guy with no training or experience. I don’t really think that’s a valid assumption, let alone a reasonable one.
TL;DR: You’re unlikely to be attacked in general. If you’re unfortunate enough to find yourself in such a situation, it’s likely you’ll know your attacker. Whether or not you know your attacker, you should try to be honest about the people you associate with and the community you’re in if you’re making assumptions about a “normal” person’s reaction. For me, that means assuming everyone knows at least the basics of grappling.
A 2014 report presented by the Bureau of Justice Statistics estimated that about 1.1% of individuals over the age of 12 were victims of violent crime that year. The probability that you’ll be the victim of a violent crime, at least in the United States, is relatively low. The crime rates for Wisconsin are even lower than national average. Let’s start with that. The probability that you’ll actually be attacked is pretty low. I don’t mean to, or want to, engage in any fear mongering that you’re going to get attacked in the first place, let alone by someone trained. I’m pretty priveledged to live somewhere that the rate of incidence of violent crime is a fraction of a percent. But since we’re talking about self-defense, we’re already assuming we’re being attacked despite our best efforts to avoid these situations.
If a violent crime were to happen to me, another BJS report would seem to indicate that it’s exceedingly likely that the assailant would be someone I know (62% for non-fatal violent crime, 73-79% for homicide, yet another report seems to indicate 85-90% for rape specifically). So, depending on if your assumption about a violent crime is a mugging turned violent, an assault, a rape, or a homicide you get a slightly different statistic, but in most of those cases, it’s more likely than not that the person committing it is someone you know. Most of the people I know train judo, jujitsu, or BJJ. We don’t know to what extent these two factors are related, so we can’t for example say I have a 35-40% chance of being attacked by someone who is trained. We’d need more data specific to this situation to say that. What I am pretty comfortable saying though is that I’m more likely than an untrained person to be attacked by someone with some degree of training. I interact with more people who are trained.
Ignoring the kind of scary thought of someone I train with attacking me though, if I’m out drinking in a certain small town, the probability that I know whoever I run into is just about 100%. It’s a pretty small Midwestern town. I also happen to know that wrestling is a required gym unit in middle school in this community, so even if it’s been 20 or 30 years since they were on the mat, at some point they learned how to sprawl, how to shoot, and how to do some basic movements/holds on the ground. No one who went through the public school system there is really untrained; just rusty at best.
Let’s assume I don’t know the person though. I’ve ended up in a bar fight in a community where I don’t know anyone – maybe out of the Midwest or in a larger city where wrestling has fallen by the wayside. If this Maine Martial Arts article is to be believed about the number of people who do a martial art, about 6% of the population trains in something. The referenced study no longer seems to be at their link to determine if that includes martial sports like wrestling and boxing. So, let’s assume the person doesn’t train. They’re in that 94% of people that have no formal training – what’s the probability that someone who’s in a bar fight has a habit of being in a bar fight such that they’re probably experienced in it? I can’t find a statistic for this one. I tried. I found some older recidivism rates which include some rates for violent crimes, but that doesn’t really tell us what we’re looking for. I would like to make the assumption that someone who is fighting like this, likely has a history of it though. It doesn’t seem very likely that I’m the first person they’re assaulting. They’ve probably been in a scuffle or two. That’s likely no equivalent for training, but it certain needs to change your assumptions about what they know or what they will do.
For me, it’s a safer to assume that everyone knows some form of fighting in general, and for the individuals I associate with and the community I’m in, grappling specifically. Although I do advocate for learning some techniques that wouldn’t work on “trained fighters” like wrist locks, these are for specific circumstances such as escorting your drunk friend out of a bar when they’ve gotten too rowdy. I also don’t really advocate for training with this assumption of self-defense since I don’t think you can wholly prepare for that situation. I operate on the premise that grappling is a tool which may be useful in such a circumstance, not it’s a guaranteed solution to get you out of there. But everyone’s assumptions are different, and these are just mine.