Jim Thorpe may meet the OP’s bill, in that he was tremendously successful, and though he did receive coaching, that coaching only happened once he was in his 20s (and took up organized sports), and he was an incredible natural athlete.
He essentially walked into a track practice at Carlisle Indian School in 1907, and, in street clothes, outperformed every member of the track team in the high jump. He immediately became the team’s best track athlete, and became their best football player soon after.
He was a member of the U.S. team in the 1912 Olympics, after spending several years not competing in track and field (instead focusing on football in those years). He was the U.S.'s representative in the pentathlon and decathlon, and won the gold medal in both competitions; across the two competitions, he won eight out of the 15 individual events, and finished third the javelin throw in the pentathlon, despite the fact that he had never competed in the javelin prior to that year.
It is obvious that in the early days of organized athletics, there were plenty of succesful competitors with little or no coaching. Sports have massively evolved since Thorpe’s days, coaching included.
Donald Thomas of the Bahamas was a mid-level basketball player at a small US college when his friends convinced him to try the high jump. Due to his jumping ability while playing basketball, they figured that he would be a good high jumper. At his first meet, he cleared 7 feet, jumping in basketball shoes. A year and a half later, he won the 2007 World Championships.
More info at wiki: Donald Thomas (high jumper) - Wikipedia That includes the fact that he was 4th in the Commonwealth Games a couple months after taking up the high jump.
I am not sure what you mean by “world class musicians” but I have heard of plenty of guitarists in rock and pop music who taught themselves how to play.
And some of them even said that listening to a teacher or coach give advice made them worse or distracted them. (A variant of the old “centipede’s dilemma” -where a centipede knows how to walk until someone asked HOW he did it.)
Because of that I cannot point out that Dick Fosbury developed his famous technique the Fosbury Flop on his own starting in high school. If I could I would point out how he had to work his way through a variety of known high jump techniques before developing the flop and that it took him years of attempting it in competition before he began recording decent heights on his jumps. Unfortunately I cannot relate that he injured his back in the process because some of the high schools he competed at did not have soft foam landing areas. And you won’t find out how his high school and college coaches did not help him in his effort, continuing to try and convince him to use the conventional western roll technique. And I really wish I could tell you how Fosbury took the gold medal at the 1968 Summer Olympics setting a new Olympic record in the process and locking in the new dominant high jump technique used by the vast majority of high jumpers.
I cannot point that out because he passed away yesterday and he is no more.
Sorry, yes, I mean classical musicians generally speaking, which (if you want a career as a soloist) comes with a lot of competition work where small differences of technique can make the difference between winning in losing, in a way that isn’t true of, say, academics (and as far as I know isn’t so much a feature of rock and pop music, though I don’t know so much about that so could be wrong?)
And in fact, for a lot of classical instruments (I know for sure about string and voice, I think it’s also true for wind and brass but don’t know those as well) you can really mess up your body if you keep playing with improper technique for too long.
Oh, and Fosbury developed his seminal techniques in the 1960’s, close to 60 years ago. Fits quite nicely with my estimate of “maybe 60 years ago” that this was still a possibility.
I remember reading a great article about a couple of white guys who moved to Africa to train with a top runner (thought it was Usain Bolt, might be wrong about that).
They were both athletes but nowhere near world class. At the start Bolt told them they could only train with him one day a week, “or they would die.” On the other days they trained on their own and they spent several months there.
When they came back one of the guys ran the 2nd fastest half-marathon in history. I’m not sure that counts as ‘uncoached’ but it’s a great story.
I’m a track geek, so that story sounded familiar. Of course, a sprinter like Usain Bolt would not be training with half marathoners. The twins are the Robertsons, Zane and Jake, and most of the claims of their results given above are big exaggerations. Here is an interview with one of them, should anybody care.
One of the spectators was Brooklyn Chess Club President Carmine Nigro, an American chess expert of near master strength and an instructor. Nigro was so impressed with Fischer’s play that he introduced him to the club and began teaching him. Fischer noted of his time with Nigro: “Mr. Nigro was possibly not the best player in the world, but he was a very good teacher. Meeting him was probably a decisive factor in my going ahead with chess.”
Not a major sport but disc golf does have an association and ranks the best disc golfers in the world. The world’s best, guys like Paul McBeth and Ricky Wysocki, were pretty much self taught and don’t have coaches. There isn’t enough money in it to justify it.
I think it not being a major sport is the reason why. When there’s billions of dollars involved, like with Formula One, the English Premier Leage, the NFL, and such, the top athletes have to pursue every potential advantage, no matter how small. With a more niche sport or something that is of more recent origin, that isn’t as necessary.