Chicago Marathon 2015 Results Analysis

By Raymond Britt (originally published by Running Competitor Magazine)

The 2015 Chicago Marathon continued to live up to its reputation as one of the most popular races in the world along several dimensions: a flat and fast course, more than a million cheering spectators, thousands of top-notch volunteers, as the entire city seemed to embrace the event again this year.

Fast facts:
  • Finishers: 37,182 finishers (out of 45,000 entrants, selected from 70,000 lottery applications) finished the race, nearly 3000 fewer than in 2014; 20,144 Men, 17,038 Women.
  • Winners: Dickson Chumba from Kenya won with an exceedingly slow 2:09:25, a  4 to 5 minute increase vs the 2:04s and 2:05s we've seen in recent years. Likely reason: no pacers this year. Florence Kipligat from Kenya won the women's race in 2:23:33.  
  • Average Finish Time: 4 hours 33 minutes and 15 seconds, a mere 10 seconds slower than in 2014.
But there's much more to the story. We've sliced, diced, crunched and boiled the results to reveal intriguing Chicago Marathon dynamics and trends to answer the following 12 questions.

1. What was the average finish time overall? What were average times by age group?

2. How many of the 37,182 finishers were in each age group?3392)

3. How did the average finish times this year compare to finish times in 2014? By Age group?

4. How much slower is the second 13.1 miles compared to the first 13.1 miles, overall?

5. How do the first 13.1 miles and the second 13.1 mile times differ by age group?

6. Let's take a 5-year View: how do the 1st and second half split times compare from 2011 to 2015?

7. How Many Chicago Marathon runners finished, by year, from 2011 and 2015?

8. What were the winning times in each of the last 5 years?

9. When analyzing top 5 Male finishers between 2011 and 2015, will we see the same pattern?

10. What accounts for the 5 minute difference in winning time compared to 2014? Decidedly slower times at all but one checkpoint. Race organizers decided against using pacers, which had been used in previous years to speed up the field in hopes of achieving a new world record.

12 and 13. Wrapping it up with a comparison of finishers by age group, 2014 compared to 2015

For more in-depth historical Chicago Marathon analysis, see the author's complete archive at