On Saturday night, Floyd Mayweather meets Manny Pacquiao in what will almost assuredly be the highest-grossing event in boxing history. The fight has been in the making since 2008, when the diminutive Pacquiao leapfrogged two weight classes and stunned the boxing world by making the much larger Oscar De La Hoya quit on his stool. In the process, Pacquiao joined Mayweather in the sport’s 147-pound welterweight division, the first time in years boxing's two best fighters had shared a weight class. Yet despite unprecedented expectations and demands, the sport repeatedly failed to make the fight a reality. Not until earlier this year did the two men finally put aside their personal differences (it had reached the point where Pacquiao once sued Mayweather for defamation) and agree to a fight. Since then, the hype meter has gone off the scale. Could the showdown possibly live up to expectations?

There’s no question that fans prefer action-packed fights to even the most awe-inspiring displays of defense. Knockout artists have traditionally been the sport's biggest stars, and no fighter in recent memory captured the public imagination like young Mike Tyson during his run as “Kid Dynamite” in the 1980s. In this respect Floyd Mayweather definitely comes up short. He’s had only three knockouts during the past decade, one of which came when an opponent, trying to apologize for head-butting Mayweather, extended his arms for an embrace and was instead met by a Mayweather sucker punch. (It was, nevertheless, a legal punch; “protect yourself at all times” is a longstanding rule of boxing.) With brittle hands that limit his ability to unload power punches and a risk-averse style, Mayweather has repeatedly demonstrated that he’s not interested in how he looks, so long as he’s winning. Even during his reign as the sport’s box office king, fans have booed and walked out of dominant but uneventful Mayweather performances.

If Mayweather won't bring action to the fight, how about Pacquiao? At one point, it would have been a sure thing. Five years ago, Pacquiao was the most explosive, exciting fighter in the sport, a human whirlwind: a brilliantly fast fighter who bounced wildly on his toes and then dove at his opponents with reckless abandon, winging punches in flurries of four or five blows that seemed to take place in the blink of an eye. But as his victories made him an international superstar, his focus seemed to wane. He ran for political office in his native Philippines and was elected to Congress after a failed presidential bid. He appeared in movies. He recorded a number of albums. He even played professional basketball in the Philippines. The Pacquiao who showed up in the ring was still great but no longer a force of nature. His body seemed to grow thicker—less a sinewy set of elastic cords and more of the heavy build of a weightlifter. Still quick on his feet, he no longer seemed to explode into his foes. The combinations of four or five punches became one or two. The knockouts, once an expected component of a Pacquiao win, dried up entirely. In June 2012, a lackluster Pacquiao was the victim of atrocious judging in a match against the solid but outclassed Timothy Bradley. Although boxing experts nearly unanimously slammed the decision, it was nevertheless a match that Pacquiao would have won handily only a few years earlier.

Pacquiao’s nadir came in December of 2012, in the fourth fight in his epic series with his longtime nemesis, Juan Manuel Marquez. The first three fights had been as close to even as boxing matches can be, and yet all had been scored either in Pacquiao’s favor or a draw. For the fourth fight, Marquez added a considerable (some would say suspicious) amount of muscle after convicted steroid peddler Memo Heredia joined his training camp. Whether it was Marquez's added muscle, a decline in Pacquiao’s ability, or simply a perfectly timed punch, Marquez caught Pacquiao with a straight right hand at the close of the sixth round, and Pacquiao immediately collapsed face down on the canvas. It was the sort of knockout from which boxers never fully recover.

After a year away from the ring, Pacquiao returned and handily decisioned the smaller but heavy-punching Brandon Rios. He then avenged the loss to Bradley, winning a firm decision in which Pacquiao clearly dominated the latter half of the fight. Most recently, Pacquiao had little trouble walking over an opponent named Chris Algieri, an unheralded former kickboxer who still lives in his parents’ basement on Long Island. Even as Pacquiao has reestablished himself as a top contender, he has yet to flash the trademark brilliance of his heyday. One has to go back ten fights, to the year 2009, to find Pacquiao’s last win by knockout. Not since 2010 has he really wowed his audience.

So what are the odds that a fight between a defensive virtuoso and a dormant volcano can gratify a decade of pent-up expectations? Not great. The most likely outcome is a dull, one-sided Mayweather win—a fact reflected in the current betting in Las Vegas. Even at his best, Pacquiao would have been an underdog against Mayweather, and fighters who share Pacquiao’s wide-open style—as exciting as it is to watch—tend to get picked apart by technically proficient opponents, of which there are none better than Mayweather. Marquez, the fighter who has always given Manny fits and who knocked him out cold in 2012, is in almost every respect a lesser version of Mayweather: When Marquez fought Mayweather in 2009, he not only lost every round, he may have lost every minute of every round.

Two scenarios could nevertheless generate an exciting fight. One would be Pacquiao turning back the clock. Reports from Manny’s camp have said he’s training with a focus and ferocity he hasn't displayed in years. His body looks tauter and more defined than it has since 2009. Perhaps most encouragingly, he and his camp have been flashing a swagger we haven’t seen in the lead up to Manny’s most recent fights. On the other hand, it’s pretty hard to believe that Manny’s decline over the past five years can be chalked up exclusively to a lack of interest. Even if none of his recent fights compare to the size of the upcoming match with Mayweather, the fights against Marquez and Bradley were big in boxing circles; they should have brought out Manny's best. And there’s still a question about all the damage the 36-year-old has sustained over 64 professional bouts. Put simply, asking for a prime Pacquiao on Saturday night is probably wishful thinking.

But Manny isn’t the only one who has aged. And this leads us to the second scenario that could make for a good fight: Mayweather may have slowed such that he can’t rely on defense to carry him to a win. Mayweather is 38, ancient for a prize fighter, and he’s looked slower and more vulnerable than we’ve ever seen in his past two fights, both against modest contender Marcos Maidana. Maidana, a wild-swinging Argentine, was able to score by bullying Mayweather into the ropes, where Mayweather couldn’t use his superior reach to keep his foe at a distance, and then unloading unanswered flurries of punches while Mayweather covered up and dodged. Mayweather had to win the fights by moving the action to the center of the ring, where his superior technical ability allowed him to dominate their exchanges. If Maidana was able to corner Mayweather, the quicker Pacquiao should be able to do so too; and unlike Maidana, Pacquiao punches with actual accuracy. He won’t miss when he has man pinned to the ropes.

Before you get too excited: Mayweather has had blips in performance before, but he always responds with great performances in his biggest fights. After looking unusually troubled against Miguel Cotto in 2012, he rebounded with blowout wins over Robert Guerrero and Saul “Canelo” Alvarez in 2013. Mayweather is still the hardest working fighter in the sport, and he has looked unusually strong in the buildup to this fight (perhaps as a psychological ploy, Mayweather has added Memo Heredia to his training camp, the same convicted steroid dealer Juan Manuel Marquez hired to help him add bulk before his knockout win over Pacquiao in 2012). Skeptics have pronounced Mayweather dead in the past but, as he’s fond of reminding people, at 47-0, he’s still undefeated.

The most likely scenario for Saturday night remains a wide Mayweather decision. Pacquiao may get off to a quick start, maybe even drop Mayweather early in the fight, but Mayweather should be in complete control by the middle rounds and should pull away late. It’s not a recipe for excitement, but it would be an exclamation point on Floyd’s Hall of Fame career, to outclass Manny Pacquiao. Whether seeing that is worth $100, especially knowing what a despicable person Mayweather is outside of the ring, is a harder decision than deciding whom to bet on.