An example comes to mind: when I first started out in martial art, there was a classmate of mine who taught himself boxing. He had all the bags, equipments, books, and back then VHS tapes, but he taught himself. He had an incredible difficult time in class because all the while he have been teaching himself (about 2 years), he did not noticed that he developed this very noticeable habit of cocking his fist before thrown a punch – his punch would begin with a backward motion before moving forward so he telegraphed his punches ALL THE TIME.
Because he did not practice kicking on his own, his kicks was actually better than his punches. Even after almost a year, I could still see him telegraphing his punches. He just could not break this habit he formed.

As for those who developed a martial art, they all had combat experience in one form or another. The lessons they learned usually was pay for by their own blood or that of others, and for everyone one who live long enough and survive enough battles to form a martial art, there must have been untold hundreds and thousands who were not so lucky. So, the martial arts that exists today were the results of lessons learned the hard way that had been pass down through the ages.
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1) You have no way to know when you are making major errors. So you will continue to practice them incorrectly.

2) You have no way to develop the timing and intuitiveness that you MUST have in order to be able to defend yourself.

3) Only a well qualified instructor can recognize your errors and correct them.

4) You can’t possibly develop your reaction timing, which is based on the opponent. Unless you train seriously with different partners, you are gambling on your ability to react correctly at the right time.

5) You can’t possibly develop the sense of distance in order to fight well, unless you have partners to train with as well as an instructor to correct you and your partner.

This is only a very simplistic view of what is necessary to truly learn something that is useful for self-defense.

NOTE: I have taught martial arts since 1973. Most of the years I owned my own dojo and taught full time. Through the years I have had at least 10-15 guys come in that had self trained themselves. Some know that they had problems. Many thought that they knew what they were doing. None of them could handle the regular students that had trained in my or another legitimate class for more than 3-4 months. Of the self trained students, a few left after finding out that they could not keep up with the beginners. Those that stayed found that they had to re-learn everything, from the beginning. This was necessary to get them out of the many bad habits that they had developed that would put them at risk in a real fight.

So what does this all mean? It means that a student will progress faster if they simply come to class. If they learn on their own or from a bad instructor, it takes them longer to learn because they have to overcome their bad habits. They must develop the techniques until they are correct and replace the bad habits.

NOTE: I think that I can speak for the senior martial arts instructors here in saying that they will agree with this.

If you want to learn, you must have a truly qualified instructor. Even after more than 42 years of training, I still seek out and train with those that have training that will keep me on the correct path as well as teach me more.

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NOTE: as for your comment about understanding why you might need an instructor to learn the more advanced techniques, I have this to say………. All highly skilled martial artists always spend the bulk of the time working on their basics. All advanced techniques will only work if your basics are good. If you self train that is not possible. Any good instructor would have to reteach you the basics to correct them before you could learn the advanced techniques.
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Martial arts training and research since 1967.
Teaching martial arts since 1973.

how do you know you are doing the movement correct?
who is going to correct you if you do the movement wrong?

done correctly a rising block is very strong, it you move the elbow over less then an inch it is very week. not many videos or books explain techniques in such intricate detail as the exact point of where the technique such as this loose power.

they tested there arts in actual combat, or they developed it in combat, take your pick.
one of my friends back in the 50’s and 60’s created his own style. he tested every technique in an acutral street fight on the streets of nyc. he also was in the hospital getting stitched up for his mistakes quite a bit.
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30+yrs ma

Wrestling, Boxing, and such we’re honed over hundreds of years. if you have that long… go ahead

other arts that were from "scratch" were made by ewhole organizations of people.

intelllegence has nothing to do with how you learn MA. you can be the smartest person on earth but you still need to know how to turn and how to stand and how to deliver. IQ is irrelevent to that. you never learn to flow, you only learn to immitate.

why not learn basics at home? same reason you don’t learn the basics of open heart surgery at home. it’s complex sh*t. you can get a book about it but you wont know exactly how to do it. you gonna practice on grandma? can you read a book about doing a slam-dunk and go try it?
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