Underwhelming
The same day as Chicago, the Eindhoven Marathon was won in 2:06:26. At Eindhoven, 2:11:23 would have put Kirui in 9th place-
https://www.iaaf.org/news/report/talum-wins-eindhoven-marathon
http://www.marathoneindhoven.nl/editie-2016/uitslagen/
Could Kirui have won a 2:06 marathon today if Chicago had been run like Eindhoven? Was Chicago "tactical" because the field wasn't deep enough for most of the elite men to go faster? Maybe I'm just spoiled by the times from the paced races in London and Berlin.