CHICAGO – The Cubs begin their playoff run on Friday afternoon but Sunday will belong to the more than 40,000 runners taking to the streets for the 2016 Chicago Marathon. The elite field includes four past champions, including 2015 winners Dickson Chumba and Florence Kiplagat.

The race lost a lot of its bite when world record holder Dennis Kimetto pulled out of the race with a leg injury. Kimetto also owns the course record of 2:03:45, set in 2013. That mark appears safe, as race organizers did away with pacesetters last year. The effect was immediate. Chumba’s winning time, 2:09:25, was more than five minutes slower than Eliud Kipchoge’s victory in 2014.

Here’s a look at this year’s men’s and women’s elite races:

The Favorite

Dickson Chumba, Kenya—Personal best: 2:04:32, 2014 Chicago Marathon

Chumba holds the fastest personal best in the field and showed last year that he is able to win a slow and tactical race by making his move in the final three miles. This will be his third running of the race and experience plays into his favor. No man has won back-to-back Chicago Marathon titles since the late Samuel Wanjiru won in 2009 and 2010.

The contenders

Tsegaye Kebede, Ethiopia – 2:04:38, 2012 Chicago Marathon

Kebede’s personal best remains 2:04:38 from his last time out on the Chicago course, when he won and set the then-course record. He was second in the 2010 duel against Wanjiru that resulted in an exhilarating finish into the final 800 meters. The 2008 Olympic bronze medalist most recently ran 2:10:56 to take fifth in April’s Rotterdam Marathon.

Stephen Sambu, Kenya—Marathon debut

Sambu was standout runner for the Arizona Wildcats in cross-country and at 10,000 meters on the track. He has transitioned to the roads with ease, posting an impressive personal best of 1:00:41 for the half marathon. Last year in Chicago the leaders went through the half in 1:05:13, which could be a comfortable pace for Sambu.

American hopefuls

Luke Puskedra, U.S.—Personal best: 2:10:24, 2015 Chicago Marathon

Puskedra had his major breakthrough as a marathoner last fall when he ran a personal best of 2:10:24 to place fifth at Chicago. He showed that the performance was not a one-time fluke when he finished fourth at the 2016 U.S. Olympic Marathon Trials. He has raced sparingly this year, as his infant daughter, Penelope, was diagnosed with Neuroblastoma and he spent some of the spring season injured. Penelope is feeling better and Puskedra has returned to the roads. He is expected to be the leading American and could finish in the top five.

Elkanah Kibet, USA—Personal best: 2:11:31, 2015 Chicago Marathon

Heading into the Olympic trials this year Kibet was an enticing pick to make the team, given that he held a solid personal best for an American and had gone for the win very early in last year’s Chicago Marathon before fading to seventh in his marathon debut. He tanked, though, at the trials, finishing 19th in 2:20:10 in the blistering conditions of Los Angeles. If he elects to remain with the leaders for the first half, he could have enough saved to battle Puskedra for the top American title.

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Diego Estrada, USA—Personal best: DNF at the U.S. Olympic Marathons Trials

Many were excited for the debut of Estrada over 26.2 after he ran 1:00:51 for the half-marathon, but Los Angeles did not go as planned and he dropped out before Mile 20. Estrada is still transitioning to the marathon and had a few minor injuries in his build-up for Chicago but should still be able to put himself in the mix among Americans. Running with the Kenyans may be a tough task but Sunday should provide a glimpse of where Estrada can take his marathoning career ahead of 2017.

Women’s Race

The Favorite

Florence Kiplagat, Kenya—Personal best: 2:19:44, 2011 Berlin Marathon

Kiplagat returns as defending champion and is coming off a podium finish in April’s London Marathon. London tends to be a fast race as the course is flat and organizers provide pacesetters. But, as she showed in last year’s run in the windy City, Kiplagat can also make a late move to win as she surged in the 24th mile for the victory. Chicago’s lack of pacers pretty much guarantees that the pace will be slower through the half than London was, and given that Kiplagat is the half-marathon world record holder she figures to be comfortable and well-prepared to strike late. Kiplagat is looking to become the first woman to defend her Chicago Marathon title since Berhane Adere of Ethiopia won in 2006 and ’07.

The Contenders

Edna Kiplagat, Kenya—Personal best: 2:19:50, 2012 London Marathon

Even at 37 years old, Kiplagat (who is unrelated to Florence Kiplagat) remains a top marathoner. Her most recent run at 26.2 was a third-place finish in February’s Tokyo Marathon, where she ran 2:22:36. Because she was not selected to run for Kenya at the Olympics this year, Kiplagat spent the summer racing 10Ks on the road. She set a personal best of 31:06 in June. It could be a good sign of what’s to come in Chicago, as Shalane Flanagan finished ahead of her in an American record and then took sixth at the Olympics (another race without pacemakers).

Saturday marks her Chicago Marathon debut. The two Kiplagats stand out on paper as the only women in the race with personal bests under 2:20. Edna has finished ahead of Florence in three of the four marathons in which they have faced off.

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Atsede Baysa, Ethiopia—Personal best: 2:22:03, 2012 Chicago Marathon

The women’s side features another past champion, as Baysa returns to the streets on which she ran to victory in 2010 and ’12. She already has one major win under her belt in 2016 with her 2:29:19 in Boston.

American hopefuls

Serena Burla, U.S.—Personal best: 2:28:01, 2013 Amsterdam Marathon

The U.S. women’s field is not as deep as the men’s, as Burla is the lone top 10 finisher from the U.S. Olympic Trials. (She took eighth in 2:34:28.) She ran 2:31 in both her marathons in 2015 and has previously said that running under 2:30 would be a successful day in Chicago. She is the favorite for the top American spot.