based on my anecdotal observations on various hobbies (from a variety of computer games to more physical hobbies), i find these are mostly true, regardless of hobbies.

- say level 0 is an average performance of a complete beginner with <1 hour experience on the subject (not just counting the experience from the hobby in question. count every experience from similar hobbies). if there are some players that mostly win against level 0 players(at least >80%), mark them as level 1 players. keep doing the same on level 1, 2, ..., n. you usually ended up with nmax of 10-30.

- obviously, not all players starts at level 0. some starts below 0 and some do better. it's possible for someone to have a starting position of level nmax * 0.8-0.9. for example, #1 CS GO player will be pretty good at any other fps games on their first play, probably better than the average people will ever be (no matter how hard the average people is trying). however, a true beginner starts anywhere near that. if nmax is 20, then i would say level 5-10 is the highest starting position for a complete beginner.

- first few level up occurs naturally from experience. you could somewhat boost this process up, but you don't need to as they happen pretty fast(it usually takes 100-1000 hours of experience on the subject, to completely exhaust those easy level up opportunities). as such, a complete beginner with an average performance (level 0), or somewhat above average performance (level 1-2) is no match to a beginner with some experience (who became level 3-6 after spending 100-1000 hours). but there are rare breed of beginner who just starts right up at level 5-10, even though they don't have any experience on the subject or anything related. these rare breed could beat a beginner with 100-1000 hours of experience, when they only got minimal experience (a few hours).

- after reaching the plateau of hobbyist (around level 5, who easily beat most beginners without much experience, but still nothing on the entire spectrum), you don't get much of auto level up by playing more games mindlessly, at least not as fast as you'd hope for. as such, if someone just mindless play more rounds without any study, it won't get them very far. even if they spend tremendous amount of time (like >10k hours), many of them won't even reach level 10.

- however, if you study about the game, you would level up significantly faster than mindless playing (though this is still a lot slower than the first few auto level ups). there are many approach, including a) watch a replay of a better player and try to mimic their play, b) study about the basic fundamentals that are not required to just play, etc. there is no single approach that can cover everything, so you're almost required to do all of them at least for some bits, if your aim is high (such as level 15+ on nmax 20 game).

- usually the main driver is analyzing the play of better players. if you don't exactly know why they make such move (this should happen a lot if you go into detail), then just memorize and and try to mimic their movement exactly. one day, you might understand (but not guaranteed), or at least try to play exactly the same on the same situation (also not guaranteed).

- but this doesn't get you to the nmax. people have their own ceilings. no matter how hard they tried, or what methods they've used, their ceilings stay the same. there is no way to break the ceiling, hence ceiling. also, it's extremely unlikely that you have a ceiling of nmax. usually, if you have a ceiling of 80% nmax, that's pretty high. average people often have 50% nmax ceiling

- usually, your ceiling is formed based on your nature + nurture. but there are some other elements, which is not directly related to your ability about the subject, but still act as a ceiling. for example, there are some hobbies that you need to spend $1k for one hour of experience, which translates to $100k spending for the basic 100 hours of experience (and this could be prohibitively expensive for many people). these type of hobbies usually have lower nmax (since much fewer people have ever stepped a foot into this type of hobby), as well as lower level requirement to become a professional player.