Small Towns Cultivate Pro Athletes: Really?

How can that be? It doesn't seem to make much difference as to NFL, PGA, MLB etc. They all seem to show a remarkable and significant difference between towns of less than 50,000 and more than 5 million. I wonder if that would hold up when comparing say 50K and 500K? There aren't that many USA cities over 5M are there?

To the left is the article as it appeared this morning, 20 September, in the Sports Section of the Wall Street Journal.

When I try to remember back to my own childhood in a small town, <5K, in the 40s/50s in rural Wisconsin, I come up with memories of playing baseball all the warm months of the year and basketball all the cold months of the year. Maybe for a month or two in the fall we played tackle football without pads but this usually led to injuries so we would quickly switch to basketball. Adults were not present at our games until high school by which time we had seen and caught many thousands of hooking or fading wind-blown fly balls. On the other hand, most kids had fathers in the small town I grew up in. Even then we had a suspicion that if you didn't play catch with your dad at a young age, you probably were not cut out for baseball.

I'm not sure where this study was published but it surely was the most interesting article in the paper today. I doubt that the final answer is given here but it is interesting to think about possible answers.