Saturday's UFC 231 pay-per-view in Toronto will feature a pair of title fights that have been a long time coming.
In the main event, featherweight champion Max Holloway will finally meet the undefeated Brian Ortega in a title bout that was supposed to take place this summer, only to be canceled over concerns about Holloway's health.
And in the co-main, former bantamweight title challenger Valentina Shevchenko will face former strawweight champion Joanna Jedrzejczyk for the vacant flyweight title in a mouth-watering matchup of two polished strikers.
ESPN's Cheat Sheets are here to tell you everything you need to know ahead of UFC 231 at Scotiabank Arena.
UFC flyweight championship: Valentina Shevchenko (15-3) vs. Joanna Jedrzejczyk (15-2)
Odds: Shevchenko -350; Jedrzejczyk +290
It's one of the best matchups in the history of women's MMA, which feels a bit strange considering it has already happened three times.
It has been 10 years, but Shevchenko, of Kyrgyzstan, and Jedrzejczyk, of Poland, are quite familiar with one another. Back in their respective Muay Thai careers, the two met in the IFMA World Championships in 2006, 2007 and 2008. Shevchenko won all three by decision and eventually moved up in weight.
How much insight those results may provide into this 125-pound MMA title fight on Saturday depends (as you may have guessed) on whom you ask.
"It doesn't matter when, where and how we fought before, every experience is an experience and I know what to expect from Joanna," Shevchenko told ESPN. "I know her power, her speed. I know everything about her."
Not surprisingly, Jedrzejczyk's perspective could not be more opposite.
"It doesn't matter at all; that was a decade ago," Jedrzejczyk said. "I'm totally different. I'm stronger physically and mentally, and my skills are better."
The history makes for a great backstory, but to Jedrzejczyk's point, much has changed since 2008. Frankly, much has changed since 2017.
The UFC's decision to add a 125-pound weight class may not have benefited anyone more than Shevchenko. Immediately, she was the front-runner to put her mark on this division. She has been forced to wait for a title fight all year, due to various situations with former champ Nicco Montaño, but this is her time now.
"The UFC creating 125 is the best thing that has happened over the last year," Shevchenko said. "This is my weight class, where I feel strong. And I see it in the future as the most interesting weight class for females."
And for Jedrzejczyk, it's an opportunity to call herself the greatest of all time, despite losing her strawweight title to Rose Namajunas in 2017. This is her third championship fight in 13 months, and she will become the first woman to win titles in multiple weight classes if successful.
"The 'GOAT' of women's MMA," Jedrzejczyk said. "I will make history in a higher weight class, against a tough opponent. I will cement my legacy as the greatest of all time."
In Jedrzejczyk's entire MMA career, only one opponent has given her fits: Namajunas. Why?
The best explanation might be in what Namajunas didn't do in her back-to-back wins against Jedrzejczyk. She didn't try to keep her down, and she didn't allow Jedrzejczyk to find the kickboxing distance where she is most comfortable.
When you think about Jedrzejczyk's dominance at 115 pounds, those were the pillars of her success. Opponents have either worn themselves out trying to take her down in the clinch, or they were eaten alive by her length, speed and volume on the outside.
Namajunas never let Jedrzejczyk settle into her deadliest range. She moved in and out and laterally to constantly change the range of the fight, and she mixed in a ton of effective feints that really seemed to throw Jedrzejczyk off. And as great of a fighter as Jedrzejczyk is, she couldn't adjust. The rematch against Namajunas went five rounds and was certainly not a blowout, but when it came down to it, Jedrzejczyk lost 49-46 on every card.
So why bring that up now? Shevchenko is a vastly different fighter than Namajunas, but there are similarities in the challenges she poses to Jedrzejczyk. She doesn't need to rely on a takedown to win, and she's going to be very tough for Jedrzejczyk to beat at range.
Shevchenko isn't going to move like Namajunas, but she is one of the most precise counterstrikers in the sport -- and she has a size advantage here. Shevchenko might be the best female fighter in the world, and we've only seen her compete in the UFC at her best weight once. The majority of her fights have been at 135.
Nobody likes to hear this, but I could see this fight taking a slower, "chess match" pace at times. Shevchenko is never in a hurry and these two are so familiar with one another. Keep an eye on the effectiveness (or lack thereof) of Jedrzejczyk's leg kicks. If Shevchenko is successfully countering those kicks, that's big.
Prediction: Shevchenko by decision