The best fighter of this era will soon emerge after Canelo Alvarez and Terence “Bud” Crawford clash for Canelo's undisputed super middleweight titles on Sept. 13 at Allegiant Stadium in Las Vegas on Netflix.

Alvarez (63-2-2, 39 KOs) and Crawford (41-0, 31 KOs) are both four-division world champions, having claimed undisputed status during their respective title reigns, while spending sustained periods of time atop many pound-for-pound lists at their peak.

Alvarez of Guadalajara, Mexico, has won world titles at junior middleweight, middleweight, super middleweight and light heavyweight. Crawford meanwhile, has been a world champion at lightweight, junior welterweight, welterweight and junior middleweight.

The Omaha, Nebraska, native became the undisputed champion at junior welterweight and welterweight, whereas Canelo has twice accomplished the feat at 168-pounds.

While Alvarez, 35, and Crawford, 37, have long been far apart in weight, they still have previous opponents sharing similarities for both heading into their superfight. Here is how Alvarez has fared against similar opponents to Crawford since arriving stateside in 2010.

Over the last 15 years, Alvarez, who stands at 5-foot-7-and-a-half and has a 70.5 inch reach, has faced six southpaws and is perfect - 6-0 with three knockouts. Those six wins have come in varying degrees, ranging from dominant victories over James Kirkland and John Ryder to being pushed to the brink over 12 rounds by Austin Trout and Erislandy Lara.

While Crawford can fight from both orthodox and southpaw stances, he's long settled in at southpaw rather than lean on his switch-hitting abilities. Among southpaws, Lara, Trout and Billy Joe Saunders gave Alvarez the best run for his money and are the closest stylistically.

Among the common themes shared was an ability to stay at the end of range, forcing Alvarez to lead. This opened up opportunities to catch and counter on his way into exchanges, while using defense, footwork and ability to outmaneuver Alvarez for success.

Alvarez stopped WBO beltholder Saunders after eight rounds to earn his third super middleweight title on his first run to becoming the division's undisputed champion. Trout and Lara were much closer to upsetting the apple cart, though he won a split decision over the former and was a unanimous decision winner against the latter 15 months later.

Crawford can move and will likely have a significant speed advantage in every department, provided his trek to 168-pounds hasn't slowed him down. However, Crawford is on his front foot and stands his ground much more compared to how Lara and Trout fought Alvarez. If Crawford finds his range early, that could open the door for him to connect with big counter punches, but that could also come with the risk of being caught by a much stronger Canelo.

Physically among the southpaws, Crawford is most similar to Lara. He stands 5-foot-8 with a 74-inch reach, while Lara is an inch taller and has a 1.5 inch reach advantage. Outside of the southpaws, Crawford's dimensions most mirror Hall of Famer Floyd Mayweather.

Five-division world champion Mayweather (50-0, 27 KOs) was the first man to defeat Alvarez in September 2013, also standing 5-foot-8 with a 72-inch reach. Mayweather dominated him from the first to the final bell en route to a 12-round majority decision.

Alvarez is far more experienced than when he faced Trout and Lara in 2013-14. Physically, he's much stronger but footwork and foot speed arguably remain his biggest weaknesses.

Alvarez has struggled to catch fighters with quicker feet, which played a big role in why his most recent outing against now-former IBF titleholder William Scull played out as it did.

One wouldn't expect, nor hope Crawford moves to that extent but with the Omaha native being the naturally smaller fighter, he'd be remiss not to use movement and ability to outmaneuver Canelo to his advantage.

Alvarez needs to keep Crawford in-front of him, either by cutting off the ring or stopping the former two-division undisputed champion using his angles to keep him turning. Alvarez's left hook to the body and ability to pressure, pushing Alvarez to the ropes will be key in helping him earn victory.

Lara, Trout and Saunders may have all fallen short but nonetheless provided some semblance of a blueprint on how a southpaw can beat Alvarez, while Mayweather's superior experience and boxing prowess negated the significant size disadvantage he was facing.

Whoever can best negate their biggest disadvantages will likely be the one who emerges victorious. For Alvarez, that means slowing the fight down and forcing Crawford to fight him in close quarters, where his hand speed and footwork will play far less of a role. If able to execute this, he'll likely have the inside track to becoming the first man to beat Crawford.