my experience not far behind these "average person" threads is some mix of modifying the baseline (ok, not quite average, really above average in some facet) or selling some ideology or training plan. it's all work rate. it's this training plan that would do it. sorry but i knew jocks who ran a full season of XC with serious workouts, fast teammates to chase, equipment, etc., never broke 20. and that's not average work ethic. my memory was how many soccer teammates and other people quit XC after 1-2 weeks of that kind of workouts. and they are above average jocks willing to drag their tookus up and down soccer fields for 90' all game. who say, woah, 2 miles of strides, 2 miles of warmups, 6 miles of intervals, haha pull the other one, i will be on the couch and at select soccer practice.
from this thread you had two people who booted or rebooted on this thread and gave times. the one guy with no prior experience who worked his butt off was in the low 20s. and not immediately, after a bunch of work. like i said. the other guy barely broke 20 and was former XC ie not average.
i agree with the poster saying these kind of posts are usually made by oblivious natural freaks who were born running 5 minute miles and had their view from the top and have no perspective on what even mediocrity or being the last kid on the varsity 7 takes. i was roughly 5th on my XC team. that equated out to i was roughly 5th in athletics period when we did our annual mile time trial -- even the throwers and jumpers. which, i was doing that before i started XC from soccer endurance.
no, you want an idea of average, it's not the 5th-7th guy on XC. they are probably 10-20 fastest distance runners in the school.
go watch a PE class run a mile. that gets timed with a sun dial. or they are walking. pick the middle kid. that's average. not the back end of XC kids who you are annoyed with because you wish you could win team. they are fairly fast and just not fast/deep enough. as someone said, your average kid in PE is either hacking up a lung or jogging or walking after a mile, lack the fitness and lungs to really race anything any distance, and would pull a muscle if they tried to explode. at best they jog along and run about an 8 or 9 or 10. this is real average.