Let's say there is skating school enrolling 4yo girls. I imagine through 1-2 first years they learn basics: sliding, falling, simpliest elements, endure the drills, stress, physical fatique, early wake ups, whatever else.
Let's assume 100 of such 6 year olds survived, are showing promise and willing to continue.
How many of them (on average) will have triple jumps?
You'd be lucky just to get 10 of the 100 past the basic 1-8 classes.
I think the basic 1-8 classes would be covered by witcher's postulated first 2 years of 4- and 5-year-olds learning basics, starting with more than 100 kids. If this is a hard training school including stress, physical fatigue, early wakeups, etc., for preschoolers, then probably a lot would drop out because they' don't have the desire or focus to work that hard at that age. If it's made fun for them and not expensive, probably a lot will stay until they're 6.
And if there's enough rigor to keep them progressing, probably they'll be doing single jumps after two years of regular training.
The single axel will be the sticking point for many of them. Six years old is pretty young to insist on an axel, if this is the kind of school that kicks skaters out if they can't keep up with the top of the class. But the ones who start at 4 and are going to get triples someday will be doing axels and at least some doubles by the time they're 8. Even those who will never rotate more than a double lutz will probably be doing at least some doubles after 4 years of steady training.
The further up you go, the more will not be able to keep up with the fast-track expectations. And if the school only keeps the ones who can keep up, or if there's only more and more expense and few incentives to keep skating if they're not progressing toward the top, many will lose interest and quit to do something else.
If preliminary and prejuvenile competitions, or whatever equivalent this system calls them, are available for both the talented and average skaters, and if the training is fun and affordable, you may still keep a lot of those 100 6-year-olds who made it past the basics in the sport for several years, working on their double jumps, although those with below-average jumping ability (or who can't afford the time and money to train as many hours) may never master any doubles and drop out in frustration.
But once they get to 9 or 10 the really talented ones will be making progress toward the double axel; one or two may even be able to land a double axel or an easy triple, sometimes. But the majority will be falling further and further behind the talented leaders, because average physical talent and great hard work is not going to be enough to get that double axel. So if reaching elite competitive levels is the goal, the kids themselves or whoever is funding the training may decide it's time to stop training once it's clear they're not going to get there. And some of them -- both those who eventually succeed and those who never will -- may get badly hurt in the attempts.
Based on what I see in my club, maybe 5% of skaters who get as far as trying single axels ever getting double axels, and less than 1% getting multiple triples, does seem like a reasonable estimate.
