The 2017 Chicago Marathon unfolds Sunday in the Windy City, and this year will mark the 40th running of the prestigious event. As one of the six Abbott World Marathon Majors, Chicago brings out big names every year in pursuit not only of the $100,000 winner's purse, but also of the 25 points toward a potential $250,000 end-of-year payout.

The race is rife with drama: world record holder Dennis Kimetto hopes to right the ship of his career against six other sub-2:07 performers; Galen Rupp is looking fit; Tirunesh Dibaba is following up her stunning 2:17 against two-time defending champ Florence Kiplagat; and a potential American marathon star in Jordan Hasay may be born.

FloTrack will be there providing wall-to-wall coverage. Here are the elite story lines we'll be following in the lead-up to the October 8 race:

Could this be the end for Dennis Kimetto?

What a peculiar career it's been for Kenya's Dennis Kimetto. The former farmer didn't begin seriously training until 2010 -- when he was already 26-years-old -- but by 2012 he was running the fastest debut marathon in history (2:04:16). Just two years later on the same Berlin course, Kimetto set the still-standing 2:02:57 world record and appeared destined for an all-time great career. Three years ago, we couldn't wait for the seemingly inevitable epic battles that Kimetto and Eliud Kipchoge were soon to wage.

Except that never happened. Kipchoge has become running's cult phenomenon and is unquestionably the GOAT, while injuries and ineffectiveness have made Kimetto all but irrelevant other than in reference to Kipchoge's pursuit of his record. The 33-year-old is still talking a big game, but with Chicago being his first race of 2017 and his first marathon in a year and a half, skepticism is warranted. If Kimetto is a non-factor on Sunday, which is certainly a possibility since the last marathon he finished was a 2:11, it's reasonable to conclude that Kimetto is done contending for wins against the best of the best. But the Windy City could be just the place to reboot his career -- Kimetto won here in 2013 and still holds the 2:03:45 course record from that run.

Then again, Kimetto can look to three other men among the 10 fastest all-time -- Geoffrey Mutai, Moses Mosop, and Patrick Makau -- as proof of how tough it is for elite marathoners to return to the top after prolonged injury.

What are the odds Galen Rupp wins?

Although there are plenty of reasons for optimism for a Rupp victory, it's wiser to take the field. Rupp is yielding loads of experience to runners like defending champ Abel Kirui and 2:03 man Stanley Biwott. Rupp will be right in the mix if he runs well, but there's a difference between being one of the favorites and being the favorite.

For the optimist, the American has transitioned to the marathon seamlessly and has quickly become one of the best marathoners in world since his debut in 2016. Rupp hasn't had to run a quick marathon yet, so it's not clear if he could pop off a sub-2:05, but given the lack of pacers and the potential rain and warm temperatures, the winning mark may land around 2:10. Rupp has run well in the second half of each of his three attempts, all tactical races in that range. He placed second in Boston despite dealing with a plantar injury in his buildup.

Several of the big names Rupp will face in Chicago have struggled lately, whether because of injury or otherwise. No one besides Dennis Kimetto thinks Dennis Kimetto is in world record shape anymore. Stanley Biwott has been injured and his last marathon attempt was a DNF in Rio. Olympic silver medalist Feyisa Lilesa hasn't broken 2:14 in his last two marathons. Among the East African favorites, only the 35-year-old Kirui enters with momentum, winning last year and coming off a 2:07 in London in April -- a reachable time for Rupp.

An American man hasn't won in Chicago since 2002, and an American-born man hasn't won since Greg Meyer in 1982. Rupp has a great shot to end that drought. At least one or two of the sub-2:07 guys are likely to be on their game, so America's greatest 10,000m runner isn't getting off easy.

Will Tirunesh Dibaba cruise to victory?

Florence Kiplagat may feel pretty good about herself as she enters Chicago looking for a third-straight victory in the race, but her confidence is probably tempered by the presence of Tirunesh Dibaba.

This will only be Dibaba's third career marathon, and her first outside of London. If there's any question mark surrounding the 32-year-old Ethiopian in Chicago, it's if she'll succeed in a race without pacers. But a 2:17 talent shouldn't fold under the relatively soft weight of variability. Dibaba ran the fastest second half of anyone in London after an insane opening 13.1, and the fact that she still had the wheels to nab a silver in the 10,000 at August's world championships shows that she is mega-fit.

Dibaba has said that she wants to "make history" in Chicago; does that mean she's chasing the 2:17:18 course record? That feat would be an extremely tall order considering warm weather and no pacers, but she remains the favorite.

How will Jordan Hasay follow up her stunning debut?

Hasay ran her first marathon at Boston in April and broke the American debut record -- a stunning 2:23. She became the fifth-fastest U.S. woman in the event, this after running a similarly brilliant 67:55 half marathon weeks before. Hasay has resurrected her career on the roads and could have many years of international marathon success ahead after transitioning to the event in her mid-20s, relatively early by American standards.

The 26-year-old seems likely to employ a similar conservative strategy that worked so well in Boston. She ran over a two-minute negative split to destroy the debut record. However, race circumstances could force her to go out more aggressively. Dibaba may not truly chase the 2:17:18 record, but she's probably also not going to go out in 72 minutes like the Boston pack did. Hasay surely won't do anything crazy and drop a sub-70 first half, but it's going to be fascinating to see how she strategizes if Dibaba takes things from the gun.

Who are the other names to watch?

Bowerman's Chris Derrick will make his debut in his hometown and finally take on the 26.2-mile distance suited perfectly to his endurance-first skills. Injuries delayed Derrick's debut over the past few seasons, but his impeccable cross country record -- three U.S. titles, top 10 at the 2017 World Cross Country Championships -- suggests he can thrive in the marathon. Derrick's Bowerman teammate Andrew Bumbalough will compete on Sunday as well, running his second career marathon. Bumbalough ran 2:13 in Tokyo in February.

Two guys with top-five finishes at Chicago will be back for more. Luke Puskedra and Stephen Sambu are flying under the radar entering the race, as neither man has the accolades or times to be counted among the favorites. But Sambu has racked up tons of wins on the roads over the last few years, and his fifth-place in Chicago last year (2:13:35) came in his debut. He's a classic sleeper, as is Puskedra, who relaunched his career at this very race in 2015.

Half marathon world record holder Zersenay Tadese of Eritrea has likely grown tired of hearing about his potential in the full considering that his non-Breaking2 PR (in which he ran 2:06:51) is still only 2:10:41. Not that the 35-year-old has really given the 26.2 miles his full attention: if Tadese finishes on Sunday, it will mark just his third completed marathon outside of the Nike event, and his first since 2012. He may not be among the very best at this distance, but his ridiculous half marathon resume (58:23!) still makes me think there's a marathoner in there somewhere.