Kenyan Rita Jeptoo and Ethiopian Atseda Baysa will duel again this after a photo finish in 2012.
The clock is counting down to the start of this year's Bank of America Chicago Marathon.
Jeptoo came in second, just behind Atsede Baysa, at last year's Chicago Marathon.
Baysa won last year's Chicago Marathon.
Tadese set the half-marathon world record.
Ritzenhein finished ninth at the Bank of America Chicago Marathon last year.
Abshero finished first in the 2012 Dubai Marathon, his debut marathon.
Kye Martin breaks down marathon street closures in Chicago's neighborhoods and gives tips for parking, public transit and expressway driving.