As any betting company will tell you, there definitely is a top x box to sit in, not saying that sitting outside it is totally catstrophic particularly in the younger cohorts i.e. Not yet 17 but increasingly as cohorts age better, as a committed remainer, in than out! It requires imagination as it's a variable and of course it evolves overtime eventually becoming history!

Until a player reaches the top 100 ,a bit like the concept of Schrödinger's cat, a cat in a box may be dead or alive at any point but you don't know with 100% certainty until you open the box. While the box is still closed who knows but after 10 years even with air holes ..... things aren't looking good.

There are confounders and as you say that's what makes watching careers interesting, often they are blinding obvious, Collegiate hiatus, injury, specific factors in their game that need addressing, attitudinal adjustment etc. however statistical correlation with markers for success is very reassuring

Back to the box the harder you look at it the less imagination/luck you need. You could look at it from a number of perspectives, from a very basic perspective at NY 18, Katie would be in it, i.e. Rank less than 400. In her cohort there is a massive drop off behind her. No players ranked between 3-400, ideally one would want to see her featuring in the top 20 not yet 19 already i.e. Playing a cohort up. Realistically if last year had been injury free I think she would be there. Given her situation and putting things in perspective given her talent level shes pretty close and that is exciting.

Generally that cohort grows year on year up to the NY 22 cohort, the earlier you get in that cohort the more likely you are to push through it and play more than a year up which is a cohort that really starts growing in the NY21 group. I don't necessarily think this is a product of a very strong 96, 97 cohort (perhaps a weak/shallow 95,94) but a product of physical, technical and tactical maturation. There are more than 20 players not yet 23 and realistically if she can keep a top 5-6 place in the 99 cohort she will be a top 100 player or better by 23.