This year, due to COVID-19 postponements, five major international marathons (known collectively as the World Marathon Majors) are all taking place within 42 days of each other.
In a normal year, Tokyo, Boston, and London would run in the spring, and Berlin, Chicago and New York would be held in the fall. But Tokyo was cancelled this year, and the rest were pushed together from Sept. 26 to Nov. 7.
It's an unprecedented crunch.
And the insanity will come to a peak this weekend, as the Chicago and Boston will take just one day apart: on Sunday and Monday respectively.