The purse for a majority of the races at Hawthorne is $10,000 to $15,000, meaning they may only take home $750 to $1,000 for winning a race. A successful jockey often participates in several hundred races a year, riding dozens of horses.

"You gotta be winning to make money. If you run last, you're paying for your own gas to get to the track," said Thornton, who has been on a hot streak of late—winning approximately 25 percent of the races he's entered. "That's hard to do. If you're winning at 15 percent, you're doing pretty good."

Slinger averages about $800 to $1,200 a week, which doesn't sound bad for a typical 25-year-old in Chicago until you break it down hourly. She works seven days a week, and often 10- to 12-hour days.

"I'm not poor, but I'm definitely not high-income. One time I got a day's check for $3,000 and I was like 'Yes! Michigan Avenue time!' " said Slinger. "Good days like that make it worth it."

WOMEN NOT ALWAYS WELCOME

In more ways than one, Slinger isn't a typical jockey.

Unlike many of her peers, she didn't grow up around horses. Instead, the 26-year-old spent her formative years in a city known more for racing on four wheels rather than four hooves—Detroit.

"I remember being 8 years old and seeing it on TV when I was a kid and telling my mom, 'I want to do that!' " said Slinger, who didn't begin to work on a farm until her teen years. At 18, Slinger fled to Kentucky with no money, car or place to live with the hope of landing at a track.

"Kentucky, you think, hey Kentucky Derby! Hell, that sounds like a good place to start," Slinger said, laughing.

She eventually found her way into a bit of riding and jockey training, but she moved to Chicago in 2011 after she found a lack of good opportunities.

"When it came down to it, they wouldn't let me on some of the top horses in the world," she said.

Part of the problem: being female in a male-dominated sport.

"As a girl, you don't really get as many opportunities," said Slinger, who is one of two female jockeys out of about 25 at Hawthorne. "I'm constantly overcoming stereotypes, especially since I have no problem being a girl. I like clothes, I like shoes. So I hear things like 'You should be someone's wife!' and I'm like 'No, I want to ride fast horses!' "

Slinger says she still runs into trainers who refuse to use her because of her sex.

"A couple days ago I went to a trainer and was like 'Hey, if you ever need any help … I'd love an opportunity.' He goes, 'Actually, I don't use girls. I don't think you're tough enough and you're too easily intimidated.' And I was like 'Really?' And then he wanted to keep me there and talk like it was socially acceptable. You get that and then some people who are like, 'Yeah, I don't mind girls, I can use you,' but then they don't really. But [Hawthorne] is one of the better places I've ever seen."

Sometimes it's not sexism nor skill that holds a rider back. It's bad luck.

Part of the jockey's job is to constantly lobby trainers and owners (or hiring an agent to do the bargaining for them) so they're able to ride their best horses. Because Meier doesn't have an agent, he often comes to Hawthorne when it opens at 6:30 a.m. and spends much of the morning talking to trainers.

There's some mornings you can get 10 races, some you won't get any, but you need to show your face every day, because it can be out of sight, out of mind," Meier said. "You gotta show up and you're selling yourself constantly."

Dorris, who trains 35 horses at Hawthorne and owns half of them, acts as a matchmaker with jockey and horse.

"You let them get a feel for the horse and establish a relationship before you go into the race," he said. "Each rider's different. Some riders are speed riders, some are closers, some are better on routes and some on sprints. It's just the same as each horse is different so you pair them up the best you can."