Nobody knows what’s going to happen when Canelo Alvarez and Gennady Golovkin finally fight Saturday night in Las Vegas.

The betting odds slightly favor Golovkin, and plenty of experts are picking Alvarez. But the middleweight championship bout between two of the best boxers in the world is about as unpredictable as a fight can get.

That’s what makes it the best fight the world of combat sports has to offer in 2017.

Technically, it isn’t the “biggest” fight of the year. That distinction belongs to the Aug. 26 bout between Floyd Mayweather and Conor McGregor. The greatest boxer of his generation and the biggest star in UFC history sold more than four million pay-per-views, putting on an event unlike any in the history of sports.

The end result, however, was never in doubt. Whether it was by decision or knockout--Mayweather won by TKO in the 10th round--the boxer with 49 career wins and no losses was always going to beat the mixed martial artist in a boxing match.

Saturday’s fight provides no such guarantee.

They are two of the most accomplished athletes in boxing. Golovkin is a perfect 37-0 with 18 consecutive title defenses at 160 pounds. Alvarez has 49 wins and one loss, with his only defeat coming at the hands of Mayweather when he was just 23 years old.   

Golovkin and Alvarez are the two best middleweights in the world, and Saturday’s fight had to be made in order to decide which one is the true king of the division.

“What Triple G are we gonna see on Sept. 16? What Canelo are we gonna see on Sept. 16? I don’t think we’ve seen the best of both guys,” Oscar De La Hoya told International Business Times. “I think on that night we’re gonna see the best of both guys. These types of fights bring out the best in you.”

Canelo Alvarez Gennady Golovkin Canelo Alvarez and WBC, WBA and IBF middleweight champion Gennady Golovkin pose during a news conference at MGM Grand Hotel & Casino on Sept. 12, 2017 in Las Vegas, Nevada. Photo: Getty Images

Golovkin’s ascent to the top of the boxing world has been unlike any other current champion. He made his professional debut in 2006, two years after winning the silver medal at the 2004 Summer Olympics for his native Kazakhstan. Golovkin came to the United States in 2010 in search of landing bigger fights, but he wasn’t able to secure one against a bonafide PPV draw until well after his 35th birthday.

As maybe the most dangerous man in boxing without the name recognition to match, potential challengers have steered clear of Golovkin.

“It’s easier to make fights for Wladimir Klitschko than it is for Golovkin,” K2 managing director and Golovkin promoter Tom Loeffler once told The Ring's Doug Fischer. “Golovkin’s got a major title and dates on HBO, which offers good money, but there’s still nothing but excuses from potential opponents.”

Just two successful middleweight title defenses shy of Bernard Hopkins’ record, Golovkin has left a path of destruction in his wake. His first 17 defenses, as well as his six fights before that, all ended the same way--with a knockout.

Since his first championship fight, only seven of Golovkin’s 19 opponents have made it beyond the fifth round. Not only was he never close to being knocked down, but no fighter ever had Golovkin in much trouble.

That is, until his last fight. Daniel Jacobs looked every bit like Golovkin’s toughest challenger to date, becoming the first fighter in nine years to go the distance with the champ. Jacobs out-landed Golovkin in power shots 144 to 126, per CompuBox, and many spectators disputed the judges’ decision.

What can’t be disputed is what Golovkin accomplished on March 18.

He went toe-to-toe with the world’s second-best 160-pound fighter, landing 231 punches to Jacobs’ 175. Golovkin proved he could win a decision against a world champion by going 12 rounds for the first time in his career, adding yet another element of unpredictability to Saturday’s fight.

“Here you have Jacobs, who is a world-class athlete, gave him a few angles, had the same punching power probably, maybe more speed, and was pushing back Golovkin,” De La Hoya told IBT. “It was a close fight, but I thought it was a fight that Golovkin won. We’re not used to seeing Golovkin go the distance. We’re not used to seeing Golovkin being pushed back. So I strongly feel that that fight made Golovkin that much better. That’s what those types of fights do for you.”

Jacobs entered the bout with 12 straight knockouts of his own. He was sent to the canvas after spending less than 10 minutes in the ring with Golovkin, suffering his first knockdown since his winning streak began.

Alvarez has been upright in all 353 rounds that he’s spent in the ring since turning pro. Golovkin has the power to knock the Mexican fighter down, and if he lands the right punch, that’s exactly what he’ll do.

“I don’t think Canelo has been in there with a guy who can punch as hard as GGG. So my question is, what’s gonna happen when Golovkin clocks Canelo on the chin? And maybe he goes down. What’s gonna happen?” De La Hoya asked. “If Golovkin hits you and gets you down, if you don’t have experience on how to get back up, he’s gonna finish you.”

Golovkin’s dominance never stopped Alvarez from wanting this fight. At just 27 years old, he’s taken on all comers. Since his loss to Mayweather in 2013, Alvarez has decision wins over the dangerous Erislandy Lara and Miguel Cotto at 154 pounds. He knocked out James Kirkland in 2015, as well as both Amir Khan and Liam Smith to retain his light middleweight titles in 2016.

Having never fought at 160 pounds before, Alvarez made the leap to 164 pounds in May for a fight with Julio Cesar Chavez Jr, preparing to become a true middleweight. He didn’t score a knockout, but he won every round of the one-sided fight, selling over one million PPV buys in the process.

Alvarez’s 2013 fight with Mayweather became the second-best selling PPV at the time. Entering that fight with 42 wins and 31 knockouts, he had the following to warrant the bout, though he wasn’t ready to defeat the best boxer in the world.

Now, Alvarez has the tools to be the world’s No.1 pound-for-pound fighter. He’s fast with improved defensive skills, and he’s one of the best body punchers in boxing. Alvarez’s power doesn’t match Golovkin’s, but it’s more than enough to end a fight in short order.

It’s time to see what Alvarez can do at the weight that most suits him.

“I think at 154 it was debilitating,” Alvarez told IBT through a translator earlier this summer. “My legs started feeling tired and weak. Fighting at 164 in the last fight, I felt so much better. It was great. So I think that 160 was the right move for me.”

Alvarez is going to land significant shots against Golovkin throughout the fight. En route to his 34 knockouts, Golovkin hasn’t been afraid to trade blows with his opponents. It’s part of what he calls the “big drama show” that he provides the audience during his fights, which has endeared him to a large portion of boxing fans.

That style could come at a price against Alvarez. It nearly cost Golovkin against Jacobs, and it made his previous fight against Kell Brook closer than expected before the challenger’s corner was forced to throw in the towel in the fifth round.

Alvarez could be catching Golovkin at the perfect time. Two years ago, he would’ve been a decided underdog against Golovkin. With the boxer from Kazakhstan in his mid-30s, Saturday’s fight is basically a coin flip.

“Triple G has flatlined straight ahead. Didn’t get better, didn’t get no worse. But he’s who he is,” Bernard Hopkins told IBT. “Every fight, if you don’t elevate your game, when others are watching, they’re gonna take your spot one day. When you’re there, there’s always someone tryna get there too. Canelo is there right now.”

Others would disagree.

Despite taking some clean shots from Brook a year ago, Golovkin’s overwhelming power sent the Brit to the hospital with a broken orbital bone. Against Jacobs, Golovkin used his power and boxing skills to maintain a clean record.

“It seems funny to me that this guy has the highest knockout ratio in middleweight history, he’s undefeated, he’s never been hurt, never been down, but yet he’s getting old,” Golovkin trainer Abel Sanchez told On The Ropes Boxing Radio. “People are funny, but I guess they hold him on such a high pedestal that everything he does has to be perfect.”

Just about anything is possible when the bell finally rings Saturday night at T-Mobile Arena.

Golovkin and Alvarez might fight to a competitive decision. There’s reason to believe that either one will score a knockout well before the 12th round.

Whatever happens, this is one fight that should live up to the hype.