2015 was a turning point for Nate Diaz. It was also a turning point for Anthony Pettis. For years, Diaz was seen as an exciting but limited fighter who would never be able to supplant the elite competitors at the top of the Lightweight division; a fun personality that dedicated fans of the sport may rally around, but not someone who would ever be particularly relevant to casual or mainstream fight fans. Pettis, meanwhile, was one of those very elites; in 2015 he looked to be not only a dominant champion inside the cage, but also a polished personality with mainstream crossover appeal outside the cage. If Diaz could have earned a shot at Pettis’s championship in 2015, it’s fair to say that oddsmakers would have significantly favored Pettis. Four years later, they are set to fight in the welterweight division in the co-main event of UFC 241, and the odds are virtually even. Obviously a lot has changed since 2015 to make oddsmakers handicap this fight as a pick ’em, and if one isn’t paying close attention, it might be easy to miss that a lot of the apparent changes are nothing more than transparent hype.

Diaz’s career obviously took a turn for the better after his lone fight in 2015, a decision win over Michael Johnson. The fight was a good showcase of Diaz’s volume striking style, featuring above-average MMA boxing skills, seemingly endless cardio energy, and impressive durability. But of course, the post-fight callout of Conor McGregor (then at the height of not only his celebrity, but of his fighting mystique after melting Jose Aldo) was what really launched Diaz’s star. In the callout, Diaz effectively came off as a no-fucks-given American gangster, and one with zero fear or even respect for the hottest star in MMA. Even if his skills didn’t seem to equal McGregor’s, his personality made him the perfect foil.

Some analysts recognized that Diaz’s jiu jitsu bona fides and impressive cardio made him an interesting matchup for McGregor (and this writer has the bet slip to prove he was one of them!), but most wrote him off, so when Diaz won the fight with a choke as a +300 favorite, the MMA world wasn’t sure exactly what it meant. Had Diaz been underrated all along? Or had he perhaps realized his previously untapped potential? Was McGregor, the man who just dethroned Jose Aldo, significantly overrated? Was it just a bad style matchup?

The answer is surely some combination of all of those factors, but it was increasingly difficult to have a reasoned discussion about Nate Diaz as his rivalry with McGregor grew. McGregor was so polarizing that virtually any discussion about him would draw in partisan “fanboys” and “haters” who had no interest in objective analysis. And of course it was impossible to measure or discuss the contemporary Nate Diaz without weighing in on McGregor. When McGregor edged Diaz in a close decision win in the rematch, for Diaz the fight seemed to at least confirm that McGregor and Diaz were worthy rivals.

Since establishing himself as a worthy rival to mega-star McGregor, Diaz hasn’t stepped inside the cage for a fight. McGregor himself has only one one-sided win and one one-sided loss since that fight, so it’s difficult to use him as a measuring stick by proxy for Diaz’s inactivity. It’s widely debated whether “ring rust” is real and how important it is if so, but the general sentiment is that long periods of inactivity don’t allow fighters to grow and develop as well as they do by staying active.

It’s been about three years since fans have seen Nate Diaz fight at all. It’s been five years since the last time he fought someone who could be called a “good grappler” (his unanimous decision loss to Rafael Dos Anjos). While that turning point callout in 2015 (and subsequent high profile bouts with McGregor) certainly afforded Diaz some new level of mystique, it’s not quite right to say that he’s demonstrated that he’s turned a corner as a fighter in that time.

This is a stark contrast from the path Anthony Pettis has taken since 2015, when his career nose-dived after losing his Lightweight title to Rafael Dos Anjos and enduring a three-fight losing streak. With his star faded and his mainstream appeal dented, Pettis found himself in the role of the fighter who had to put his nose to the grindstone and run a gauntlet of tough tests. While Diaz fought just twice after his 2015 win over Michael Johnson, the fighter who fans once derided with the nickname “Shelftime” fought 9 times in the same period. Those 9 fights have been in the Featherweight, Lightweight, and Welterweight divisions, and saw Pettis post a 4-5 record. The four wins include submissions of lauded grapplers Michael Chiesa and Charles Oliveira, and the only knockout loss of karate fighter Stephen “Wonderboy” Thompson’s career.

That brings us back to the present, days before Diaz and Pettis do battle, with oddsmakers handicapping the fight as virtually too close to call. Why is this fight being seen as such a close contest? Part of it may be the perception that Pettis has declined since his run as a dominant champion. That three-fight losing streak definitely hurt Pettis’s stock, but it’s also been three years since that run of bad performances. While “Wheaties Box” Pettis may be in the rearview, losing-streak-Pettis is in the rearview too now. Pettis has never stopped training, never stopped striving to improve, never stopped testing himself against the best opponents in the world across three divisions. In short, reports of Pettis’s decline may be greatly exaggerated.

Of course, part of it is also that Diaz’s star has risen. But a glance at Diaz’s record demonstrates that that ascension is as much a product of hype as of real marked improvement. Diaz’s two performances against McGregor were real accomplishments, but it’s hard to say how relevant they are (if at all) in assessing how Diaz will perform in 2019.

In analyzing fights, like in anything, it is best to focus on actual, measurable knowledge, and to minimize assumptions. Fight fans know that if Pettis has one weakness, it is his durability, and that Diaz is extremely durable. But unlike Pettis’s recent opponents Dustin Poirier or Tony Ferguson, Diaz is more of a high-volume striker than a power striker, and he rarely throws elbows, kicks, or anything other than punches, so it is hard to imagine him breaking down Pettis’s body the way those opponents did.

In 2015, most would have said that Diaz had no path to victory against Pettis. Pettis’s losses since then have showed us at least one potential weakness, but his wins since then should be weighed at least equally. And while Diaz’s star has risen in that time, fans should not assume his growth as a celebrity is proportionate to his growth as a fighter.