A showdown for middleweight supremacy invades Las Vegas on Saturday as unified titleholder Gennady Golovkin and lineal champion Canelo Alvarez square off in one of boxing's most anticipated matchups in years. 

Golovkin (37-0, 33 KOs), the knockout sensation from Kazakhstan, and Alvarez (49-1-1, 34 KOs), the Mexican superstar and current face of the sport, will enter T-Mobile Arena (HBO PPV, 8 p.m. ET) with a shot at securing the defining victory of their respective careers. 

Let's take a look at the biggest storylines surrounding the fight entering Saturday.

1. Forget Floyd Mayweather-Conor McGregor, this is boxing at its best: For as much crossover attention and constant talk within the 24-hour news cycle that was created by Mayweather's return from a two-year retirement when he stopped the reigning UFC lightweight champion in August, the fight was nothing more than an entertainment spectacle. There are credible arguments to be made in either direction as to whether the timing of Mayweather-McGregor and the attention it caused will prove to be a negative or positive to the financial bottom line of Alvarez-Golovkin. 

But Saturday's fight represents something far more important to the sport than any carnival sideshow can provide (no matter how entertaining or lucrative said fight turned out to be). Canelo-GGG is a reminder of how good the sport can be -- how it used to be -- when one simple philosophy matters most: the best fighting the best. In this case, the two best at middleweight just happen to be two of the most popular fighters in the entire sport. This is very much boxing's Super Bowl and the best it can offer in terms of competition, 50/50 matchmaking and the potential for explosiveness. 

2. It's not out of the question that the winner exits as P4P king: With a pair of victories over the last 12 months over Sergey Kovalev, then ranked no worse than fourth on most pound-for-pound lists, light heavyweight champion Andre Ward finally secured his day in the sun as boxing's P4P king. The voting for such imaginary lists are largely subjective, of course, which means there are just as many media outlets who have recognized Golovkin in recent years as the sport's best fighter. Mixing that with Alvarez's growth and current standing as an elite fighter means Saturday's fight could offer more at stake than just the outright middleweight championship. Depending upon how impressive the victory turns out to be, the winner of this fight just might find himself deserving to be called the best boxer in the world regardless of weight. 

3. Alvarez can solidify his placement among Mexican greats: With his movie star looks and cerebral style, Alvarez hasn't always had the easiest time securing adoration from certain sections of the hard-core Mexican fan base. For all of his talents, Alvarez has never been the traditional come-forward warrior, willing to absorb three punches in order to land one. But even if he's not a clone, per se, of the great Julio Cesar Chavez Sr., Alvarez has done well to carve out his own niche as a popular champion. With a style that's more in vein of Juan Manuel Marquez, Alvarez has gained his respect over time. If there's still a criticism following Alvarez, it's that he hasn't yet taken down someone deemed a physically dangerous threat to him. But he'll certainly have such a chance against Golovkin and a victory would do more for the status of Alvarez's legend among the Mexican greats than any other in his career.

Canelo can win over a lot of Mexican fans on Saturday night. Getty Images

4. Canelo's chin is very good -- but it will need to be great: If you're looking for video of Alvarez acting adversely negative to a punch landed against him inside the ring, only one piece of major evidence is readily available. Alvarez took on Jose Miguel Cotto, the older brother of Miguel, in 2010 and a well-placed left hook from Cotto caused a still 19-year-old Canelo to wobble back into the ropes. For years, the highlight was used by Alvarez's naysayers to outline his lack of a chin. But a funny thing has happened since that day -- Alvarez has yet to have another hiccup since. To most, that would be evidence of a very good chin (although, if we're honest, Alvarez hasn't entered too many fights in which he wasn't the bigger man). But his chin is going to need to be great to withstand the kind of sustained power he will face against Golovkin, who knocked out 23 consecutive opponents until Daniel Jacobs went the distance against him in March. 

5. Alvarez could be catching Golovkin at perfect time: Unlike the soap-opera build toward Floyd Mayweather-Manny Pacquiao in 2015, when boxing fans were forced to wait more than five full years to see the two superstars finally face off in their late 30s and well past their prime, the build to Saturday's fight hasn't been nearly as painful. One might argue that the two-year build for Alvarez-Golovkin might actually help the fight do more business than it would have done 18 months ago, when the majority of experts would've predicted a clean knockout by GGG. Alvarez has steadily evolved since those days and enters the fight on a much more level playing field in the eyes of most. One has to wonder, however, just how much the 35-year-old Golovkin's age has to do with that. 

While GGG, who didn't make his U.S. debut until age 30, still passes the eye test in terms of the perception that he remains in his prime, his close victory over Jacobs raised certain questions about his invincibility. There are many -- Golovkin included -- who believe Alvarez wouldn't have accepted the fight had GGG not looked human against the determined Jacobs. Those same people might be right. Golovkin, who has been one of the boxing's most active elite fighters in recent years, doesn't have the exact same aura he once did. Are we penalizing him too much for one close fight? We'll find out on Saturday. Either way, Alvarez's reluctance in delaying the fight has only appeared to help his chances.