"Half the money I spend on advertising is wasted; the trouble is I don't know which half." - John Wanamaker

The question is WHICH of those 80 hours account for 51.2% of the value of 10K hours of practice. It's not necessarily the FIRST 80 hours.

It's very possible you could get 8% of your skill in less than a second; it just might come at a lightning-strike eureka or moment of epiphany during hour 8,679.