Malcolm Gladwell's book, "Outliers", stated a hypothesis: becoming good at something takes about 10,000 hours of practice.
I've recently been wondering how long a typical piano student has practiced by the time they complete grade 8. Obviously there would be huge variation but an experienced piano teacher presumably would know roughly how much practice a student at grade X level is doing and how long they are typically at grade X before moving on.
For bonus points, I'd love to see an estimate of hours for each grade. e.g. perhaps grade 1 is 50 hours; grade 2 100 hours and so on.
If a grade 8 student is doing 3-4 hours a day, 6 days a week, for 50 weeks; that's 900-1200 hours just for grade 8. But are those numbers realistic?