Kelvin Kiptum, Conner Mantz, Emma Bates, and Galen Rupp were among the notable names announced by Chicago on Tuesday.

Hassan took down one of the gretest marathon fields in history in London but she'll have her hands full with defending champ Ruth Chepngetich (2:14:18 pb), just 6 weeks after Worlds.

Chepngetich is now #2 all time, 14 seconds shy of Brigid Kosgei's world record.

Can Ruth Chepngetich & Seifu Tura repeat? Who are the Americans to watch outside of Mantz & Sisson? And who is Haven Hailu?

Emily Sisson hasn't raced a fast marathon in years. Can she get the American record in her return to the 26.2 distance? "We’re hoping around 69:30 [for a halfway split]," Treacy said. "Get to 20 miles, see where you are, see how you’re feeling and then hang on or pick it up."

• MB: Emily Sisson's buildup has been spectacular. She plans on going out in 69:30. Will she get the AR?

It's not very often that an American with multiple NCAA crowns and a 13:10 5000 pb makes his marathon debut in the prime of his career, but that's happening this week for Conner Mantz. Mantz's debut is the biggest for an American since Galen Rupp.

• MB: Conner Mantz says 4:46 pace at altitude feels "comfortable" - Indicates he will go out in 1:03 at Chicago Marathon

We can't ever remember seeing this happen in an elite marathon and doubt we'll ever see it again.

Ryan is bullish on Sara's fitness heading into the 2021 Chicago Marathon - "She’s definitely done workouts that she’s never been able to do before and [she’s] super confident, feeling great" - but acknowledges the warmish forecast may take the AR off the table.

We share our six biggest storylines with you and introduce you to the new men's favorite - Reuben Kipyego - whom we just learned was running the race today.

Just as he did in Boston earlier this year, Lawrence Cherono won a thrilling sprint finish for the title today in Chicago. Meanwhile, former NOP teammates Mo Farah and Galen Rupp both struggled but 10 Americans broke 2:12.

Paula Radcliffe's legendary 2:15:25 world record is history after 16+ years.

American record alert. Jordan Hasay says she's going out in 70 flat.

Jonathan Gault has a hard-time believing one key answer Rupp gave at today's press event. When asked when did he learn that Salazar had been charged by USADA, Rupp said, “I read about it on the news, I think like everybody else.” As for what type of shape Rupp is in, Rupp himself wants to know. “I’m kind of wondering about it too, to be honest,” Rupp said.

The world's best marathoner Brigid Kosgei is racing Chicago and that means Paula Radcliffe's 17-year-old course record of 2:17:18 is in jeopardy. Could Deena Kastor's American record also fall?

How will Rupp do in his first race since last year's Chicago and in his first since Alberto Salazar's ban? Should defending champ Mo Farah be considered the favorite or should that honor go to Boston champ Lawrence Cherono?

Chronic foot issues led to flare-ups in other areas, which caused the 36-year-old to withdraw ahead of the race on October 13. He still plans on racing the Olympic Trials in February.

We break down what it all means as we we get closer to the 2020 US Trials. Plus, why we think Berlin might be a better option. *MB: 2019 Chicago Marathon US field is out: Cragg, Derrick, Ritz Join Rupp & Hasay

Does this mean that Farah is out of the 10,000 at Worlds since it takes place one week before Chicago? Jordan Hasay is also going to the Windy City as well.