It’s one of the most profound things I’ve heard of self-defense over the years: Just because it worked doesn’t mean it works… and just because it didn’t work doesn’t mean it doesn’t work.

The question of whether a technique, a method, a martial art, or even a strategy will work lies at the heart of all discussion about self-defense. There is a cottage industry online — and there has been for years — of declaring that such-and-such a technique won’t work, such-and-such a martial art is useless, so-and-so an exponent of such-and-such system is a bed-wetting pansy who can’t punch his way out of a wet paper bag, and so on.

The reason it’s so easy to proclaim that a technique, a system, or a person doesn’t work or can’t fight is because all discussion of self-defense is largely theory. Unless you’re going out and getting into actual fights, you have very little idea what you’ll actually do when someone is trying to murder you. You have no idea if the things you’re training to do will serve you well or fail you “for real” unless you’ve done them for real. In civilized society, this relegates most self-defense and martial arts training to the realm of theory.

You can mitigate these issues. Realistic levels of contact and resistance, including asymmetrical training that is “alive” in nature, are best. This is training that allows for techniques to be trained at or near full speed and full force, through scenario training, combat drills, padded assailant and torso dummy work, etc. Of less value is sparring, which nonetheless has value. It’s definitely a great way to get comfortable with applying techniques on a resisting opponent and with testing your abilities and your resolve in a relatively “safe” environment. The problem with sparring for self-defense training, though, is one of mindset. It (unavoidably and by definition) turns what should be an asymmetrical conflict into a symmetrical contest.

When sparring, both opponents are trying to win on the same grounds and within the same context. The way to win a self-defense altercation is not to fight the other fellow fairly, after all. It is to avoid the fight entirely if you can and employ a grossly unfair strategy and method (such as using a force multiplier in the form of a weapon) if you must. This is why the notion of “pressure testing” a technique is only true to a point. Unless that opponent is trying to murder you, your technique or method is only “proven” within a controlled sporting context. Yes, you may be very skilled at Brazilian Ju Jitsu… but those “proven” techniques become something else entirely when the man you’ve just pinned starts stabbing you.

Let’s circle back around, then, from proclamations of what does and does not work — of varying degrees of value — to the concept itself. What does that statement — “just because it worked doesn’t mean it works… and just because it didn’t work doesn’t mean it doesn’t work” — actually mean?

Everybody can tell a story about a ridiculous technique that should not have worked, yet did. Many long-time students of martial arts can also recount bitter stories of their training failing them when they were attacked “for real.” I know a young lady who used a technique straight from her Wing Chun class that allowed her to subdue a drunken lout at a concert who tried to get a little too “hands on.” I know another, rather obnoxious British bobby who was fond of telling anyone who would listen that a Karate reverse-punch was all he’d ever needed “on the street.” Anecdotes abound. What they have in common is that you may be able to pull off an improbable technique and you might fail to apply a “high-percentage” technique. The context matters.

More broadly, anyone can lose a fight at any time. Anyone can have a bad day. Anyone can make a mistake. And anyone can get lucky. Some of you are more confident in what you do than others of you. That confidence may be well founded or it may be unrealistic. In the case of the latter, there will one day come a reckoning that you will find unpleasant. It’s up to each of us to determine if we fall into that camp or not.

While we can dress it up with an air of scientific analysis by calling them “high percentage” and “low percentage” techniques, almost everything works sometimes. A wrist lock that won’t work on a mugger (unless you shove a thumb in his eye first) might be just the thing to subdue your drunken Uncle Phil at a party when he’s getting out of hand. A good, solid round kick will almost always work, in that it will impart force reliably to the target; a punch to the face will work whenever your fist can take it and his jaw can’t; a knife in the guts will “work” in that it will do serious, possibly lethal harm to the opponent (but may not stop him from hurting you before he dies). A “pressure point strike” that relies on “chi” and woo-woo wishful thinking will never work.

The mistake some make is in declaring an all-or-nothing judgment on entire swaths of martial training occurring in the world. We can no more say that all traditional martial arts don’t work than we can say that all mixed martial arts training does. Tae Kwon Do has become, in many circles, a watered down joke, but Tae Kwon Do as practiced in Korea can be quite brutal and effective. There are numerous awful Wing Chun schools out there, but also some incredibly adept practitioners of that system who absolutely would kick your ass if you tried to mug them. There are Mixed Martial Arts exponents who have been killed by much less fit, much less skilled individuals who had knives. There are reality-based self-defense instructors who have been shot on their way to gun-disarm seminars.

The list goes on. We can no more arrogantly proclaim that all practitioners of a given style or system “can’t fight” than we can say that all of them can — unless and until we evaluate every single one of them. Even if we have a high degree of confidence (or lack thereof) in a style, system, or category of “fighting,” there are always exceptions. Sparring (to a degree), rolling with someone (to a greater degree), and combat drills with appropriate resistance and contact (to a matching or even better degree) will help you identify those techniques and methods that tend to work. The results will always be subject to context, to individual skill, to individual will, and yes, to luck.

Reduced to its absurd conclusions, what this means is that absolutely nothing works in self-defense. Fortunately, though, we know that it can and does. This is reality, which at times can be harsh. It is all the hope and impetus we all need to keep on training.