Jacob Kiplimo, defending champion, lines up in Chicago with a chance to break the marathon world record. Kiplimo ran 2:00:28 in London, 59 seconds off the current record. Kiplimo would need to run 1:59:29 to break it.

Chicago has a history of setting world records, with Steve Jones, Khalid Khannouchi, and Kelvin Kiptum all achieving it. Kiptum’s 2:00:35 record lasted until Sawe’s 1:59:30 in London. Kiplimo’s 2:02:23 win in Chicago last year was strong, but he needs more speed. Read more culture coverage.

Kiplimo’s main competition, Amos Kipruto, ran 2:01:39 in London. Sawe and Kejelcha, who ran faster, are absent. Kiplimo’s chances depend on weather and Kipruto’s ability to keep up. Related: Sharon Lokedi's Chicago Marathon: A Test of Flat Course Speed.

This original Runner World brief is based on reporting from Marathon Handbook. Visit the source for its complete reporting, context and any later corrections.