Check out my rankings within each division by clicking on the links below. If there is a lineal champion in a weight class, he is ranked No. 1.
Who is the best fighter regardless of weight class? See ESPN's pound-for-pound rankings.
For a list of the current champions in all weight classes, click here.
Note: Results through Feb. 20. In an effort to provide the most up-to-date rankings, ESPN.com's division-by-division boxing rankings will be updated every Tuesday.
More divisional rankings
Middleweight - Junior middleweight - Welterweight - Junior welterweight
Lightweight - Junior lightweight - Featherweight - Junior featherweight
Bantamweight - Junior bantamweight - Flyweight - Junior flyweight/Strawweight
HEAVYWEIGHT DIVISION (UNLIMITED)
1. Tyson Fury (25-0)
England's Fury ended the 9½-year reign of Wladimir Klitschko in November 2015 but twice pulled out of their contractually mandated rematch in 2016 because of a litany of personal problems that have kept him away from the ring. Fury twice tested positive for cocaine and has also admitted to alcohol and mental health issues. On top of that, Fury faces allegations that he used performance-enhancing drugs in a fight before he faced Klitschko, which could lead to a multiyear ban from the sport. With so many issues, and unable to defend the belts, Fury gave up his alphabet titles but remains lineal champion.
2. Wladimir Klitschko (64-4)
During his 9½-year title reign -- second-longest in heavyweight history -- Klitschko successfully defended the title 18 times, third-most in division history. He had an 11½-year undefeated run and won 22 fights in a row. Then he defended against England's Tyson Fury in November 2015 and showed virtually nothing, perhaps growing old before our eyes. But a loss is a loss, and Klitschko's historic reign came to an ignominious end. Since the rematch with Fury was twice called off because of his personal issues, Klitschko went without a fight in 2016. He will return in 2017 for a showdown with titleholder Anthony Joshua (18-0) at Wembley Stadium in London. Heavyweight title fights get no bigger.
Next: April 29 vs. Joshua
3. Deontay Wilder (37-0)
Wilder, a tremendous puncher, has scored knockouts in all four of his title defenses, albeit against lesser challengers in Eric Molina, Johann Duhaupas, Artur Szpilka and Chris Arreola. In Wilder's most recent defense in July, he faced Arreola because a mandatory defense against Alexander Povetkin scheduled in May in Russia was canceled because of Povetkin's positive drug test. Wilder pummeled Arreola and stopped him in the eighth round, but broke his right hand and tore his right biceps, sidelining him for the rest of 2016. Wilder was due to return against Poland's Andrzej Wawrzyk (33-1) on Fox in prime time, but Wawrzyk tested positive for steroids, leaving Wilder to face replacement Gerald Washington (18-0-1), a better opponent, instead.
Next: Feb. 25 vs. Washington
4. Luis Ortiz (27-0)
A 6-foot-4, 240-pound southpaw with raw power, Ortiz had a falling-out with Golden Boy Promotions and signed with Matchroom Boxing in England and fought twice in 28 days. The Cuban defector with tons of amateur experience scored a one-sided decision against unwilling Malik Scott on Nov. 12 in a horrible fight, then hammered overmatched David Allen in a one-sided seventh-round knockout on Dec. 10 on the Anthony Joshua-Eric Molina undercard. The talk that "King Kong" could return this spring against rising contender Jarrell "Big Baby" Miller (18-0-1) seems to be fading. An eliminator against former titlist Bermane Stiverne (25-2-1) is also possible.
5. Anthony Joshua (18-0)
Joshua won the Olympic super heavyweight gold medal for Great Britain in 2012 and has steamrolled his first 18 opponents as a pro, including a two-knockdown, second-round knockout victory against paper titleholder Charles Martin in April to win a belt, and a seventh-round knockout of Dominic Breazeale in a one-sided thrashing in Joshua's first defense in June. Nothing was different in defense No. 2 on Dec. 10, when Joshua smashed journeyman Eric Molina in the third round, a victory that set up a megafight with former long-reigning champion Wladimir Klitschko (64-4).
Next: April 29 vs. Klitschko
6. Joseph Parker (22-0)
When Tyson Fury vacated his two sanctioning-body belts, it put New Zealand's Parker in position to face Andy Ruiz Jr. for one of the belts on Dec. 10. In one of the biggest sporting events in New Zealand history, Parker overcame a slow start and managed to edge Ruiz by majority decision to claim the title and become his country's first heavyweight titleholder. Parker's first defense will be a mandatory against Hughie Fury (20-0), Tyson's cousin. Parker's team won the purse bid and the fight will take place in New Zealand.
Next: April 1 vs. Fury
7. Kubrat Pulev (24-1)
Bulgaria's Pulev, who got knocked out in a title shot against then-world champion Wladimir Klitschko in November 2014, has won four in a row since. On Dec. 3, Pulev's first fight in his home country, he hammered washed-up, out-of-shape former titlist Samuel Peter for three rounds. Peter quit with an apparent right hand or arm injury just after the bell rang to begin the fourth round. Pulev is on track for another title shot.
8. Bermane Stiverne (25-2-1)
Stiverne won a vacant title by a sixth-round knockout of Chris Arreola in May 2014, and in his first defense promptly lost it by one-sided decision to Deontay Wilder in January 2015. Stiverne has fought once since, a competitive 10-round decision win (in which he got knocked down in the first round) against journeyman Derric Rossy in November. Stiverne was supposed to face Alexander Povetkin (30-1) for a vacant interim title on Dec. 17 while Wilder recovered from injuries, but 20 hours before the fight, Povetkin failed his second drug test in seven months and the fight was canceled.
9. Andy Ruiz Jr. (29-1)
Ruiz, who has tremendous hand speed but is not always in the best condition, traveled to New Zealand to face Joseph Parker for a vacant title on Dec. 10 in a bid to become the first heavyweight of Mexican descent to win a world title. He came up just short of the goal, dropping a majority decision in a fight that was exceptionally close.
10. Dillian Whyte (20-1)
Whyte, the British champion, outpointed former world title challenger Dereck Chisora on Dec. 10 in an epic slugfest that was one of the best fights of 2016. The victory was Whyte's fourth in a row since a knockout loss to Anthony Joshua in December 2015.