As you know once in awhile I post on a topic related to Martial Arts rather than calisthenics. I watched a video today that prompted me to write. For the background you have to keep in mind what has happened in the martial arts world over the past ten years or so. In case you've been living under a rock, you should watch this video.

MMA fighter vs. Kiai Master

This video is emblematic of how what people call "traditional martial arts" has slowly been uncovered to reveal more and more about what actually goes on. No matter what art you practice you cannot get away nowadays with claiming you have a secret death touch or that you can project chi blasts and knock people down without touching them. In other words, the internet has helped to make people aware of bullshit. This video is an extreme example of calling people out on their bullshit, but you get the point.
As you may know I spent about twenty years practicing Aikido. I trained with and was friends with more than a few police officers and even to this day, though I don't practice Aikido anymore, they will tell you that Aikido has served them very well in their jobs. If you ask any MMA practitioners or any of my jiujitsu friends they'll probably tell you that Aikido is a joke. I have quite a bit of experience in other martial arts so I feel confident to speak to what I've learned. I spent about twelve years in Uechi Ryu karate doing tons of sparring, ad another five years doing submission grappling (no-gi Brazilian Jiujitsu). I've also been exposed to some catch wrestling and Filipino martial arts.

The video that spurned me to post was this one:

Joe Rogan and "Aikido Guy"

And then just for completeness, it's helpful to listen to this last video too:

Joe Rogan on self-defense

Now I' not a Roagn fan boy but I'm not a basher. The general idea of what he is trying to convey I agree with 100%. And I'm not here to try to defend Aikido against his rant or defend any martial art....sort of. There has been way too much exploitation I feel in some arts and even in Aikido. But you also have to use some logic beyond just "this works and this doesn't."
The idea that the only way to train martial arts is to train against similarly trained killers is a little too simplistic, now hear me out. More importantly, and what Joe Rogan unfortunately misses is context. You'd be an idiot to try to argue that Aikido better trains people to wrestle then does Wrestling. You'd also be an idiot to try to argue that Aikido trains people to be better at a boxing match than training at a boxing gym does.
When it comes to trying to figure out what arts work best for a certain scenario like a cage match, that ship has already sailed. The answer is boxing, Muy Thai, kickboxing, BJJ, and wrestling. Some people would throw in Judo, Sambo, and some karate styles too. There is a reason for this, and you don't even have to go down that boring road of rules vs. no rules, or the possibility of weapons or anything like that- those arguents have already been played out and are understood.
What Rogan said at one point was telling: "that stuff only works against people who don't know what the fuck they're doing", referring to Aikido. What I realized at that point was the error of context and why so many cops I'm friends with and why so many longtime bouncers I've met have the extra piece or "the rest of the story". To answer it simply, there are some situations where punching, kicking, breaking an arm, or snapping a neck are inappropriate. Certainly there are non-lethal options in most martial arts so I wouldn't argue that Aikido has the answer there, just that its somethign to consider.
In contrast, there are situations where it is completely expected that you would snap someone's neck or disarm someone and then stab them- generally reserved for soldiers during wartime, and a few extremely small and unlikely scenarios.
Rogan's main error there was context again, but here it was the assumption that every battle would necessarily be a duel. Dueling is different from fighting (research this to fully understand what I mean). That said, dueling methods cannot be ignored and won;t go away just because they are dueling techniques. Most have tremendous value, just not necessarily in the context you want to use them in.
I teach my students that even though most MMA arts (mentioned above) are sports, this doesn't magically make the skills these sports ingrain meaningless in no-rules combat. In the same way that a  BJJ player might be used to five minute rounds and not used to weapons, the "reality combat" aficionado has to respect that being comfortable taking someone down and mounting them is a skill that stands alone and must be learned and practiced to do and defend against. To put it another way, there are fundamental skills and concepts that are mandatory for any and all types of fighting, sport or non-sport when it comes to "no rules". And purposely refusing to learn them puts you at a
disadvantage, period. Just because it's truly "no rules" doesn't mean that fundamental skills taught in sports are worthless. On the contrary- those skills are very important, just not in the same context and not generally in the same application. Take two knife fighters or two soldiers or two gun specialists (unarmed) or two chi-masters of equal size, age, skill, experience, and size and have them be forced for some reason to fight for their life with no rules...my money is on the one who has better fundamental skills and also the ability to be creative. Again, all else being equal. (Which is rarely the case).