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Although he enters Saturday's unification bout to crown the first four-belt undisputed champion in super middleweight history, unbeaten IBF champion Caleb Plant doesn't have to look too far to realize how much he is being counted out ahead of the biggest fight of his career.  

Most of that, to be fair, is because of the greatness achieved over the past decade by his opponent -- WBA, WBO and WBC champion Canelo Alvarez (56-1-2, 38 KOs), who holds the rare distinction of being the undisputed pound-for-pound king along with boxing's biggest global star.

But even though every single major sportsbook has given Plant (21-0, 12 KOs) the kind of wide odds as an overwhelming underdog that make this fight inside the MGM Grand Garden Arena in Las Vegas (Showtime PPV, 9 p.m. ET) feel like nothing more than a formality, the numbers don't tell the whole story.  

Plant, 29, may not have anywhere near the same elite-level experience of Alvarez, the Mexican icon who turned pro at 15 and went on to take the reins from Floyd Mayweather as the sport's biggest pay-per-view draw. Plant does, however, possess an intangible that played a major role in the promotion of this fight and might threaten to do the same in terms of affecting his chances of winning on fight night.  

Throughout a life that has been lived anything but easily, it might be hard to quantify just how mentally tough Plant truly is.  

It's why he never backed down from Alvarez as a press conference skirmish broke out between the two on Sept. 22 in Beverly Hills, California, which left Plant with a cut below his left eye. It's also why he never backed down after the melee from still approaching the podium and delivering an impassioned speech about the extraordinary life he is trying to live.  

"I have conquered things way bigger than boxing, things that would chew [Alvarez] up and spit him out and I've come out of it with my chin up," Plant told Showtime's "All Access" cameras ahead of the fight. "He knows what he has got in front of him. He's just another guy to me. 

"He's used to people coming in and just bowing down to him and handing over their belt and being happy for their check or whatever. I don't give a shit about none of that. That's not why I am here or why I fight."

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To be fair, Plant's small sample size on the highest level play just as big of a role in him being such a huge underdog in this fight as Alvarez's sublime skill. But it's clear throughout the build to this life-changing opportunity that Plant has left no stones unturned regarding his preparation and that he fully believes in the unshakable confidence he has worn as a shield when talking about the challenge ahead of him.  

"All the adversity that Caleb has faced in his career, all the hurdles that he has had to overcome, there is no such thing as a problem anymore," Plant trainer Justin Gamber said. "He can overcome anything and that is the key to winning. You see him getting meaner and meaner as the fight gets closer. I would describe Caleb's mentality as a junkyard dog. That's what you need to be a top fighter in boxing. You have to have the skill but you have to have the grit, too, that dog in you." 

The dog inside of Plant was groomed throughout a series of personal ups and downs that began within humble circumstances in Ashland City, Tennessee. Plant's mother, Beth, battled drug addiction that made a childhood surrounded by poverty and despair all the more difficult.  

Plant would find an outlet for his pain in boxing thanks to the urging of his father, Richie, who made the most of the meager resources available to them and created a ring of his own by putting tape on the ground in the shape of a boxing ring and using other parents to join arms to provide a barrier of ropes.  

"Boxing is really important to me. It has done a lot for me and I feel like I'm forever in debt to this sport," Plant said. "Where I am headed in life, there is no turning back. There is not a Plan B. I'm going to see this thing out. This is a one-way trip." 

Although a strong amateur career would lead to an alternate spot on the 2012 Olympic team, Plant never found himself in a favored spot where things came easily. In fact, personal tragedies would only continue to challenge his rise in the boxing ranks when, while competing at a national amateur tournament, he would find out his newborn daughter, Alia, was headed in a downward spiral.  

Plant, whose former partner, Carman Jean Briscoe-Lee, gave birth to his daughter when Plant was just 20 in May 2013, quickly found out Alia had been born with a brain abnormality that led to hundreds of seizures per day. He would go on to join her bedside throughout a series of excruciating months before her death at 20 months old, which included Plant making a promise that he would one day return with a professional world title in her honor. 

That day of bittersweet triumph would come in 2019 when Plant floored Jose Uzcategui twice en route to a unanimous decision to capture the IBF championship.  

"I told her I would bring it to her and that's what I did," Plant said. "You lose someone and it kind of puts a different perspective on time and to not be out here wasting it because it's valuable." 

Three months later, however, Plant's personal life would see yet another tragedy when his 51-year-old mother pulled a knife on a police officer inside an ambulance and was shot and killed by a deputy following a tense standoff.  

Although a lifetime of difficult hurdles could have broken others in his spot, Plant chose to turn his pain into a continued passion for the sport he has given his life to.  

"I have been boxing a long time, at a high level, too. I have a lot of experience in high-pressure situations, whether it's in the ring or out of the ring and they both kind of help each other," Plant said. "I'm just waiting for the bell to ring so I can just show these people who I really am and show [Alvarez] who I am. He is going to find out the same time that everybody else finds out when they thought I was just a push over and they found out too late." 

Only time will tell whether Plant's choice to poke the bear ends up helping his chances on Saturday or hurting them. Either way, he is prepared to go out swinging, if necessary.  

"November 6 is me getting my hand raised by any means necessary," Plant said. "People say that, 'by any means necessary,' but I have had to really by any means necessary, no matter what, just to sit in front of this camera right here. So I know what that means firsthand." 

Who wins Canelo vs. Plant? And which prop is a must-back? Visit SportsLine now to see Brandon Wise's best bets for Saturday, all from the CBS combat sports specialist who has crushed his boxing picks in 2021, and find out.