That's just not true with pool, and possibly other things as well. I would agree that any capable person can become at least an A player with the right amount of practice and dedication.
However, not every single person will become top tier, and it doesn't matter how much they practice.
I firmly believe that every person who is not mentally or physically handicapped can reach top tier in pool. I believe that it very much matters how much and how they practice.
The assumption is that if you take a 45 year old B player and give him 10 hours a day with a top level coach then he still can't reach the upper level and I say that I do not believe it. So far no one has really tried so we don't know do we?
I don't believe in a complete plateau, but I do believe that everyone stops having significant improvements after a certain point.
You say that but can you point to any person who spent ten hours a day practicing who did not become world class?
My point is that plateaus happen because effort stops.
Of course improvements get smaller over time. Every semi pro can be expected to run out an open rack but how many will run out if the cue ball is stuck to the rail a couple times?
SVB practices this so if his make % is 70% vs 40% over the rest of the field then that plays out in his favor over many games and matches.
The idea that a person has limits is limiting. And the catch22 is that a person cannot know their limits until they have truly tried to go as far as possible.
After all the crusaders did not know there was no Holy Grail until they went halfway around the world looking for it. Sometimes you just have to go and see things for yourself to find out how far you can go.
We could look at some of the pros and ask them? Why isn't Tony Robles ranked higher? Hunter Lombardo works and yet is himself a world class player who works on his game but HOW much does he work on it? Look at Max Eberle, a guy who is always there, always a threat but just seems to be not quite in the elite ranks. He decided to focus on straight pool beofre the DCC and managed to get a good win over Dennis Orcullo in the Straight Pool Challenge on 10ft tables. Would he have done so well without the effort?
We don't know but Max himself gives the extra practice credit for improving his 14.1 skills.
Mosconi, toured with Greenleaf playing straight pool every day for months, very competitive got beat when they started out and ended up with a close record at the end. Toured himself for years and played 14.1 every day. Thousands and thousands of hours a year. How can you not learn every shot, every move, every situation under those conditions?
SVB - monster dedication, endless hours of patient study to understand everything possible with the cue ball. This is what it takes to not only understand the subtle difference of an inch too far but to have the skill to park the ball where you want it constantly.
So my point is that every top player you find they have put in the time and the time is generally commensurate with what level of player they are.
Oscar Dominguez? He is on here as Mexpoolplayer so we can ask him. He is a top player, world class for sure. He was born with a world class coach and has certainly put in time but he also has a job installing tables with his dad. So while Shane is practicing Oscar is putting tables together. Does this make a difference? I think it does. I don't think that Oscar is less talented than Shane I think he is simply in a different position in life that does not afford him the same opportunity to focus exclusively on pool playing that Shane has. Maybe I am wrong but the fact that Oscar spends less time working on his game in my eyes plays out on the table between himself and SVB. Even though Oscar might have a winning record against Shane he doesn't have the same success in events overall and I think it's because he doesn't put the same hours in.
Of course we can't really take just two players and compare them this way and say that THIS is the only reason. But the research in Talent is Overrated showed that the biggest difference between the best performers and the next level was very simply hours of practice. There were NO elite performers who had the same amount of practice as the lower level group but were still elite.
No, ALL the elite performers had about the same amount of lifetime practice time in and that amount of time was significantly higher than the next tier lower. So I guess we will will have to disagree on this because I think humans place their own limits on themselves far more than whatever natural limitations might be there.