With four main governing bodies, and a few other less prestigious organisations who sanction fights in boxing, there is sometimes a little confusion on what all the belts mean.
Putting all of those titles and terms together certainly can be a mouthful. What do they all mean, and what is the purpose of them all? The guide below explains all the boxing hardware and phrases associated with them.
Lineal champion
The lineal champion is defined as "the man who beat the man." Its history can be drawn back to the late 1800s with John L. Sullivan in the heavyweight division at a time when there was considered one true champ. The person who beat that champion then became "The Man."
Some lineal champs in the heavyweight division include legendary names such as Evander Holyfield, Mike Tyson, Muhammad Ali, George Foreman, Joe Frazier and Sonny Liston.
Unified champion
A unified champion is one who holds two or more of the major sanctioning titles (IBF, WBA, WBC and WBO). Fury was a unified champion, and Anthony Joshua was a two-time unified three-title holder.
Undisputed champion
An undisputed champion is a fighter who holds all four major championship belts (IBF, WBA, WBC and WBO). Since the four-belt era began in 2004, there had not been an undisputed heavyweight champion at the time of writing. The last undisputed champion in the heavyweight division was Lennox Lewis back in November 1999, when he defeated Evander Holyfield in their rematch.
IBF
The International Boxing Federation was officially formed in April 1977. At first, it was treated as a regional sanctioning body aligned with the United States Boxing Association. Then in 1983, the IBF was recognized as a major sanctioning body.
IBF president Daryl Peoples explained to the Sunday Puncher in February 2018 how the organization goes about determining mandatory challengers for their champions.
"In the IBF we like to have elimination bouts, so we have the No. 1 and the No. 2 positions unranked until we find the two highest available contenders to fight for the No. 1 position," Peoples said. "Once you win an eliminator for No. 1 or No. 2, that makes you eligible to be a mandatory contender and fight for the championship."
WBA
The World Boxing Association, the oldest of the four major sanctioning bodies, was formed in 1962. The WBA has two championships: a "Regular" and a "Super" titleholder.
If a fighter has a WBA title, but then wins either the IBF, WBC or WBO belt, they get moved up to WBA "Super" champion. The "Regular" title then becomes vacant for two contenders to compete for.
The WBA determines its mandatory challengers the same way as the IBF. The "Regular" heavyweight champion is Daniel Dubois and the "Super" titlist is Usyk. It is unlikely they will fight each other and instead will defend their separate belts.
WBC
Many boxers regard the World Boxing Council as the most prestigious heavyweight belt in the sport. The WBC came into existence one year after the WBA in 1963. The WBC has held some of the most high profile fights in the history of boxing, including both Wilder vs. Fury fights. When you're the WBC champion in any weight class, many pundits consider that individual to be the premier fighter in their respective division.
Regarding the customary green belt, there are 161 flags of the countries that represent the sanctioning body. The WBC has four different types of championships. The Diamond belt, which is an honorary championship given to the winner of a historic fight, such as when Floyd Mayweather Jr. and Manny Pacquiao fought in May 2015. The Silver belt is essentially considered a secondary belt. The Eternal Championship is designated for titleholders that have never lost the belt or retire undefeated while having a series of consecutive title defenses.
In terms of the mandatory challenger, a champion is supposed to make one title defense a year, but a step-aside fee can be negotiated so a voluntary championship can occur.
WBO
The World Boxing Organization is the youngest sanctioning body of the four major titles. The WBO came into existence in 1988. However, it wasn't fully recognized as a major world title until 2004, when it got the final blessing from the WBC. Like the WBC in the heavyweight division, a champion has to defend the title once a year.
The WBO handbook says it rates its fights by the quality of competition, frequency of competition, positive television exposure, good relationship within the WBO community and no drug-related problems.