One woman is the five-time world cyclocross champion, traveling across the Atlantic to defend her rainbow jersey outside of Europe for the first time. The other has never won at worlds, medaling three times, but is the newly coronated World Cup champion, racing worlds on home soil for the first time.
Vos is the undisputed queen of bike racing. She's the reigning Olympic and world road champion, and has not been beaten at the world cyclocross championships since 2008, when she took silver behind German Hanka Kupfernagel.
Compton has come as close as possible to winning worlds, twice taking silver. In 2007, she finished second to Maryline Salvetat of France; Vos finished seventh in that race. Compton again finished second, in 2010, behind Vos.
During the 2010-11 season, Compton went undefeated in World Cup competition, taking five wins. But she opted not to start races in Plzen, Czech Republic, and Pont-Chateau, France, instead making a win at the worlds in Sankt Wendel, Germany, the focus of her season. She finished a heartbreaking second to Vos, and missed the World Cup title by a mere 10 points as well.
And for all of her accomplishments, the rainbow jersey is the final, elusive title Compton is lacking over a career that has amassed nine consecutive national titles, 16 World Cup victories, and most recently, a first-ever American World Cup overall title.
Simply put, there's one major barrier between Compton and a world title, and it's the woman who has worn the rainbow jersey for the past four years.
Each rider brings a unique set of skills and circumstances to Louisville.
Compton, 34, produces tremendous power and is without peer in challenging, muddy conditions; Vos, 25, has incredible speed and is a world-class sprinter. Compton has raced in Louisville on four occasions; Vos will be visiting the Eva Bandman Park course for the first time. Compton will have the home-field advantage, but also tremendous pressure; Vos will be out of her element, but has much less to lose.
During the 2012-13 cyclocross season, the two have squared off at three World Cup events. Compton beat Vos in Namur, Belgium; Vos beat Compton at events in Rome and Zolder, Belgium. Compton won the World Cup overall; however, Vos did not start her season until midway through the series.
Sunday's world championship race could well shape up into an epic battle between two champions -- and Compton's best-ever opportunity to claim the rainbow jersey.
"I expect a real close race," Belgian cycling commentator Renaat Schote, of Sporza, told VeloNews. "It would be great and a real duel. I would be surprised if anyone else steps up, but if we come into the last lap with those two, it would be amazing for women's cyclocross; it would be a real thrill."
Compton, however, hopes she doesn't come into the final lap with Vos, knowing that the Dutchwoman's finishing speed is a dangerous final weapon in her arsenal of skills.
"It's going to take a great day for me to win," Compton said. "It depends a lot on course conditions, if it's frozen or muddy, or maybe just slick, it just depends on who has been going better. She has the advantage if it's a speedy course, and I do better if it's a heavier course. She's good at so much, but for her, the best case would be lots of accelerations, lots of on-and-off efforts on a fast course. She's pretty speedy."
The perfect scenario, Compton said, would involve rain and mud. "Ideally, I'd like it to be heavy, just an epic race. It's always been a fast course at worlds, and I'm tired of having frozen, fast courses at worlds. I like rain and mud, where all of the different cyclocross skills come together, rather than just going fast on hard ground. I like a heavy, hard and a good fight, where you are battling against form, battling the course and battling the competition. If it’s not like that, I'm just going to race the best I can and try to be smart."
The forecast for Louisville calls for a massive temperature drop late in the week, with a high of 25 on Friday, and the possibility of snow showers on Saturday. The forecast for Sunday's race is a high of 40 and partly cloudy. Torrential rains buffeted the park on Wednesday, creating a mud bog down the road at the masters worlds venue, but Eva Bandman features better drainage, meaning Sunday could still turn out to be tacky or even dry.
Vos, who has been training in Cleveland, Texas, since Jan. 21, said she sees Compton as her biggest threat, although she wouldn't focus her race on simply beating the American.
"I'd say we are the two big favorites for worlds, but I think in the world championships you always have to watch out for other names," Vos told VeloNews. "It can be all season, me and Katie, but another name might surprise, you never know. But for sure, Katie has had a good season so far. And I'm happy with my shape so far, so it's right to see us as the big favorites."
Asked what each rider would need to do to beat the other, Vos said it would amount to a battle between Compton's power and her own speed.
"She'll hope that it's muddy," Vos said. "For me, I don't really care much about the weather or the course; I'll race if it's fast or freezing or muddy. If it's muddy, Katie is really strong, she can use her power, then it's really hard to beat her. Normally I can use my speed to beat her, and she can use her power to beat me. It's going to be interesting, I think."
Schote said that in order for Compton to beat Vos, she would need to "put pressure on Vos constantly," and hope that she can force the Dutch rider to make a mistake, as she did on the tricky and dangerous Namur World Cup course in December.
"The small things will make a lot of difference," Schote said. "I believe that Katie has the advantage by racing at home. She knows how to prepare on U.S. soil. Vos will have to adapt. Her usual surroundings won't be there, she won't have her usual camper. It's all about the little things. Of course the build-up for the race can be important, and at the end the legs will tell, but I believe a huge amount of little things will decide the outcome."
As for pressure, both riders said it wouldn't play a major factor or provide an advantage to one rider over another.
"I'm not feeling any more pressure than I usually do," Compton said. "It feels easier, because it's at home, and there's so much support, so much excitement for the race. I'm super excited to have it here, for everyone to come to see the race. It's not pressure for a result; it's just excitement for a great race, for everyone that wants to see me and Marianne go head to head. It's the same pressure whether it's a worlds here or in Europe. I'd love to win, it's always something I want to do."
Vos, 25, said that pressure on the big day is what she thrives on -- evidenced by her 2012 Olympic and world road titles. "Of course, as defending champion you want to win it again," she said. "There is always pressure for worlds, but those are the nerves, the thrill, that you want to feel. That is what you work for as an athlete, that's the one race where it has to happen. Of course you hope everything is going to go well, but in cyclocross anything can happen -- a crash, or a flat tire. And while I'll hope that won't happen, I always focus on what I can handle and be prepared for."
As for Compton, Vos said her American rival could handle the pressure. "She's an experienced rider," she said. "She will use it as extra motivation for the race."
One thing that's for certain, Schote said, is that Vos is only interested in winning. "For Vos, second or third place is a defeat," he said. "She can't stand losing."
Vos didn't disagree with that assessment.
"After five world titles, I'm not going to be happy with losing," she said. "Of course, if someone is better, I will have to accept it, but I only go for the world title."