Quoting from Wikipedia:
The OODA loop has become an important concept in both business and military strategy. According to Boyd, decision-making occurs in a recurring cycle of observe-orient-decide-act. An entity (whether an individual or an organization) that can process this cycle quickly, observing and reacting to unfolding events more rapidly than an opponent, can thereby "get inside" the opponent's decision cycle and gain the advantage.
There isn’t all that much to say. Training can shorten your loops, allowing you to get inside a less trained person’s loop. Fast loops are good, slow loops are bad. Being unpredictable even to the point of chaos is generally an advantage if it keeps forcing the opponent to re-loop without being able to execute an effective action.
The problem with martial arts games of all types (wrestling, boxing, MMA, push-hands) from a fighting point of view is that they limit you. When you have a lot of training and you are suddenly confronted with a new set of rules which deny you those training options or action, you will likely get stuck. Why? Because you train for speed, and when you train for speed certain conditions will trigger a certain kind of action. If you train to pull off particular types of set-ups, or throws or strikes, your body will just start doing them when the opening appears. If the rule set doesn’t allow it, you will have to spend a second stopping your body from making the move. Your mind can get stuck making sure that you really aren't allowed to do what your body has trained to do. Your body won’t believe that it isn't allowed to do that thing which has worked so well in the past until it has had time to adjust to the new set of rules.
If you are training self-defense, you are training people to break the rules, to do the unexpected, to temporarily abandon social constraints.
This is related to the observation that oftentimes martial artists aren’t able to use their training in a surprise attack. The conditions just don’t seem right, you’d have to keep telling yourself, yes, go, do it now. The second time you get attacked it probably has a better chance of working, but who gets surprise attacked twice now-a-days?
The OODA loop is also important for training to win games in which both people are trained with the same set of rules. It is still possible to be faster and more difficult to predict. There are also things you can do to disorient or shock your opponent. A great deal of tai chi is focuses on the disorientation aspect of the OODA loop.
One of the interesting training questions that comes up in partner work is the distance vs. action ratio. Acting first usually trumps waiting because it forces the opponent to re-loop, dealing with an attack rather than attacking. But if you are ready for an attack there is a certain distance where any action is a mistake because it will reveal your intent too soon, giving the opponent time and options for a powerful response. This is why in Greco-roman wrestling, for instance, there are these long stand-offs where both wrestlers are waiting for the other person to make a mistake. Swords and knives have this quality too, as long as both parties want to avoid getting cut any thrust of the knife makes the hand vulnerable to attack. Tai Chi is famous for playing in this close quarters realm where whoever acts first loses. But of course a player of great skill will disorient their opponent on contact.
OK I've said enough about that. It came up a while back with Tabby Cat, who has a new video.
The problem is obvious if you watch it. The guy Tabby is pushing with looks like a loaded gun forced to keep the "safety" on. He sees ways to act, but then remembers he isn't allowed to do that: OODA loop shut down. It's very different then two people who train with the same set of rules. There is something else important and valuable to see here, namely that Tabby is easily uprooting his opponent by using his opponent's tension. It is a very difficult skill to learn because you have to comprehend what is happening and melt all the tension in your body. But what I always look for in a Tai Chi guy is, can they do it in the form? Can they do it in a big range of motion? Can they do it to the side? Up, down, left, right, front, back, circle? From behind? On the ground? or over their head? (While sipping tea is my goal.) Notice he only has the skill upward from a low position close to the body. That would be the easiest position. Sort of like treading water in the deep end of the pool. Swimming in the arctic it ain't.
Anyway that is my conceited opinion and that is what I was thinking when I got to the later part of the video where he wraps the red pregnancy cloth around his arms. OK perhaps it is because I've been doing too much relaxation of deep unconscious tension lately, but when I saw that, I just about busted a gut! Now that we know you can tread water in the deep end, why not try it in the kiddie pool!
Well, if you've read this far I have a little treat for you which is mostly unrelated. I have been thinking about advice to give beginners who what to go far in internal martial arts. Here is my advice. Don't try to make any technique work. It is quite counter intuitive, but the problem is, if you try to make a technique work you will be conditioning yourself to feel either 1) a type of active resistance, or 2) success. The problem with the feeling of active resistance is that when you actually have the internal gongfu you won't feel any resistance. The problem with the success feeling is that when your technique fails in a violent confrontation you are likely to freeze. Now I don't know from experience that the feeling of success in a flaw, but my gut tells me it is. Anyway, to win by force is a mistake. What we want is that you just practice the techniques, if there is resistance change, if not keep going. In the beginning it is the outer forms that really matter. Know the technique, don't try to make it work. A subtle difference perhaps, but I'm finding it is a powerful teaching key.