The details are in the Week That Was, but one Japanese high school coach, Hayashi Morozumi, has coached as many current sub 2:10 marathoners as all of America.
Here is the marathon times the top 3 guys coached by Moruzumi ran in 2018:
Suguru Osako 2:05:50
Yuki Sato 2:08:58
Akinobu Murasawa 2:09:47
America had one sub 2:10 guy last year, Galen Rupp. There are only 3 guys still running professionally in the US who have ever broken sub 2:10 (Rupp, Dathan Ritzenhein, and Abdi Abidarahman) and none of the other 2 have done it in 5 years.
This is simply amazing. And it begs the question, what are we doing wrong on the men's side in America?
And while googling about sub 2:10 marathons I found an article from nearly 30 years ago lamenting how few sub 2:10 guys there were. Not much has changed except the bar internationally keeps getting faster and faster.