There are about 600,000 high school track athletes per year. Call that 150,000 per class and 75,000 boys, as a conservative estimate. You are saying that it is pure chance that 5 out of the top 20 (25%) high school distance runners of all time wound up at Newbury Park. If there have been 60 years in the modern era (around Jim Ryun) of, on the very low side, 30,000 boys per year in the country running track, to have any one of the top 20 from those 60 years would be a 0.0011%. Treating each family as 1, since you seem to think that if there is one great runner in a family, every other sibling will be great, which is nowhere near true, we can square that and get a probability of 0.0000012345% of having two of the top 20. Statistical probability of having 5 of the top 20 of 1,800,000 would be infinitesimal. Face it, Brosnan is just that good a coach. He brought a pro-style program to NP, adapted it to high schoolers, and sold it to them. His results were better by far than any other U.S. high school distance coach ever.