Shelby was the most obvious doper in the race, come on. I don't think Kipyegon and Tsegay are clean either, but they at least have a gradual progression from the beginning of their career. Shelby's progression is the following:
2019 3:54.99 Khalifa International Stadium, Doha (QAT) 05 OCT 2019
2018 3:57.34 Pontaise, Lausanne (SUI) 05 JUL 2018
2017 4:06.22 Alexander Stadium, Birmingham (GBR) 20 AUG 2017
2016 4:03.39 Hayward Field, Eugene, OR (USA) 28 MAY 2016
2015 4:09.62 Liège (BEL) 15 JUL 2015
Ridiculous, has to be just like DeBues-Stafford (second most obvious doper of the final) on some really good stuff
I don't think they do the same training. From an interview in 2011 with Salazar (can't post link thanks to anonymous poster restrictions): "Jerry and my group are definitely different. We both train out of the Nike campus, but he could just as well or I could just as well be in another state. They are a totally separate group. So my group is known as the Oregon Project, because the Oregon Project was built around my philosophies and my beginnings in coaching eight years ago. And Jerry's group has a totally different identity, and he has totally philosophies of training and so forth. "