I believe that a number of these matches between Jenkins and Cheserek involved them trying to tie at the line, though by coincidence or Cheserek's intention, Cheserek won each of those by the barest margin.
The Oregon Relays 5k saw them separated by .03s in 2014. They were separated by .02 at the Stanford Invite at 10k where they were just running a qualifying time way back, and the same at the Pepsi Invit in 2015 at 5000m (.02). At Pac 12 5000m, the margin was .08. At NCAA 2015 10000m, Ches took Jenkins offguard in sprinting at the end to win by .79 and he beat Jenkins by .25 at the 5000m that meet.
The only substantial margins for Cheserek were NCAA 5000m (8.7 seconds) and NCAA XC champs (4 seconds) in 2014.
Jenkins' two victories were not by leans, .61 at NCAA 3k in 2015 and 1.08s at Millrose in 2016. In other words, Jenkins wasn't much behind Cheserek and since then Jenkins has run substantially faster times at 3k, 5k, and mile (3:49 5th Ave. Mile).