There's always a lot of talk surrounding the best pound-for-pound boxer in the world. After Manny Pacquiao defeats Juan Manuel Marquez for a third time, Pac-Man will have made his case that he's the best in the world.
To take it one step further, another win over Marquez will cement Pac-Man's legacy of being one of the greatest of all time.
Boxing has had its fair share of legends. From Muhammad Ali to Sugar Ray Robinson, they've all had their personal rivalries that pushed them to that next level and created some of boxing's most memorable moments and matches.
For Pacquiao, no rival has been more intertwined in his legacy than Marquez. Despite holding a 2-0-1 record against him, it has always felt like they've been equals. The first fight, an instant classic, ended in a draw. The next two fights saw Pacquiao named the victor but were covered in controversy and really could have gone either way.
The fourth encounter will go a long way in deciding how boxing fans look at the whole history of this rivalry.
A decisive win for Pacquiao justifies those that feel Pacquiao won the second and third fights. A loss for Pacquiao and those who feel Marquez won the second and third fights will have more credence to their claims.
Furthermore, how Pacquiao fares in the fight will impact how we view the latter part of his career.
There's no questioning Pacquiao's impressive resume. He's been atop the sport for more than a decade now. He's the only boxer to ever hold titles in eight different weight divisions. His staying power has been more than impressive, and he's made a case that he's the best of all time.
Where does Pacquiao rank in boxing history?
However, after a controversial decision loss to Timothy Bradley, the way we view the end of his career is in serious jeopardy against Marquez. If he is unable to beat Marquez this time around, the perception will be that he has held on too long.
Nothing hurts a legacy more than trying to hold on for too long.
When we think of Evander Holyfield, we don't just see his brilliant performances against Mike Tyson, Buster Douglas and Riddick Bowe, we unfortunately see three straight losses to Chris Byrd, James Toney and Larry Donald.
When we think of Mike Tyson, we see the dominant performances of his youth, but we also can't shake the image of a much older Tyson being battered by Lennox Lewis or getting knocked out by Danny Williams and Kevin McBride.
When history looks at the greatest boxers of all time, there is a penalty for holding on too long. If Pacquiao can notch a convincing win to close out his rivalry with Marquez, he will show that he is capable of finishing out his career with the same dominance that he performed throughout it.