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.
For a list of the current champions in all weight classes, click here.
Note: Results through Dec. 18. 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
WELTERWEIGHT DIVISION (UP TO 147 POUNDS)
1. Keith Thurman (28-0)
The hard-hitting and exciting Thurman claimed a well-deserved split decision against Danny Garcia on March 4 at Barclays Center in Brooklyn, New York, to hand him his first loss and unify world titles in a heavily-anticipated match, Thurman's second in a row televised on CBS in prime time. Thurman, however, will be out for the rest of 2017 after having surgery on his right elbow. He plans to return in February or March for a soft defense but has spoken of eventually wanting to meet Errol Spence Jr. to unify titles.
2. Errol Spence Jr. (22-0)
Spence was the best pro prospect from the 2012 U.S. Olympic team, the 2015 ESPN.com prospect of the year and has lived up to the hype as a pro. He was sensational in both 2016 fights as he destroyed former junior welterweight titlist Chris Algieri by fifth-round knockout followed by a brutal sixth-round knockout of Italy's Leonard Bundu in a title eliminator that set the stage for his May 27 shot at a world title against Kell Brook. Spence traveled to Brook's hometown of Sheffield, England, and overcame a slow start to score a decisive 11th-round knockout victory when Brook, who had been dropped in the 10th round, retired because of a broken orbital bone. Spence's first defense will come against his longtime pal Lamont Peterson (35-3-1) on Showtime.
Next: Jan. 20 vs. Peterson
3. Manny Pacquiao (59-7-2)
After a brief retirement following a one-sided decision win against Timothy Bradley Jr. in April 2016, and subsequent election to the senate in the Philippines, the all-time great Pacquiao returned on Nov. 5 and ran roughshod over Jessie Vargas. Pacquiao scored a second-round knockdown and won a unanimous decision against a man 10 years younger than him to regain a welterweight world title in an excellent performance. In his next fight, which was July 1 live on ESPN, Pacquiao faced massive underdog Jeff Horn in his hometown of Brisbane, Australia. They put on an action fight and although Pacquiao appeared to be the clear winner, Horn was the recipient of a gift hometown decision. Pacquiao, who nonetheless did not look very good, said he wants the rematch and promoter Bob Arum was planning it for November, but Pacquiao has said he will not be available then, so it could happen in 2018.
4. Danny Garcia (33-1)
Former junior welterweight champion Garcia headlined a January 2016 card on Fox in prime time and although he struggled early against Robert Guerrero, he came on strong in the second half of the fight to win a vacant belt. Then, in November, he fought at home in Philadelphia in a horrific mismatch with Samuel Vargas in a nontitle fight. Garcia abused Vargas en route to a seventh-round knockout, paving the way to a unification fight with Keith Thurman, who won a split decision to unify world titles on March 4 in a big-time fight. Garcia, for no apparent reason, fought only once in 2017.
5. Shawn Porter (28-2-1)
In June 2016, former titlist Porter challenged pal Keith Thurman for his belt and they put on one of the best fights of the year. It was an all-action fight that Porter lost by 115-113 on all three scorecards. Porter wanted an immediate rematch but was denied and instead returned April 22, when he knocked out former two-time titlist Andre Berto in the ninth round of an eliminator to earn the rematch as one of Thurman's mandatory challengers. But with Thurman out because of an injury until at least early 2018, Porter didn't want to sit around so he faced tough Adrian Granados on Nov. 4 and maintained his mandatory status with a grueling, but one-sided decision victory.
6. Kell Brook (36-2)
Brook made three welterweight title defenses but against lesser opposition in Jo Jo Dan, Frankie Gavin and Kevin Bizier. When no top welterweights would face him Brook moved up two weight classes and challenged unified middleweight champion Gennady Golovkin in September 2016 and was stopped in the fifth round when his corner threw in the towel as he was getting battered. Brook, who suffered a broken right orbital bone and had surgery, elected to return to welterweight to make a mandatory defense against Errol Spence Jr. in May but suffered another stoppage loss, this time when he retired in the 11th round because of a broken left orbital bone. Brook underwent surgery to repair the fracture in June and is now ready to return. He is moving up to junior middleweight and will face tough Sergey Rabchenko (29-2) in what is by no means a gimme fight.
Next: March 3 vs. Rabchenko
7. Jessie Vargas (28-2)
Vargas, a former junior welterweight titleholder, lost his welterweight world title in his first title defense in November 2016 when Manny Pacquiao knocked him down and outclassed him to win a lopsided decision. Vargas, whose contract with Top Rank expired in 2017, aligned himself with adviser Al Haymon and returned to headline a Premier Boxing Champions card against Aaron Herrera (33-7-1) on Dec. 15. Vargas shook off the rust of a 13-month layoff with a shutout 10-round decision victory.
8. Lamont Peterson (35-3-1)
Peterson, a former junior welterweight titleholder, edged Felix Diaz by majority decision in a controversial result in October 2015 and then was out of the ring 16 months before returning on Feb. 18 in a strong performance against the solid David Avanesyan. Peterson won a competitive unanimous decision and secondary world title. He vacated the belt on Oct. 3 and will challenge for the title held by Errol Spence Jr. (22-0) on Showtime.
Next: Jan. 20 vs. Spence
9. Jeff Horn (18-0-1)
Horn, a former Olympian and former school teacher, got the opportunity of a lifetime when Manny Pacquiao agreed to come to his hometown of Brisbane, Australia and give him a shot at his world title. They met July 1 on ESPN and it was an exciting fight. Horn showed enormous heart and determination but appeared to fall well short of victory. The judges, however, saw it differently and gave him a very controversial decision and the title. Plans for a rematch with Pacquiao were canceled when Pacquiao elected to sit out the rest of 2017, so Horn instead defended against England's unknown Gary Corcoran on Dec. 13 and stopped him in the 11th round of a one-sided fight. Horn is due to face mandatory challenger and former undisputed junior welterweight champion Terence Crawford (32-0) in April.
Next: TBA vs. Crawford
10. Lucas Matthysse (38-4)
Argentine slugger Matthysse, known as "The Machine," challenged Viktor Postol for a vacant junior welterweight world title in October 2015 and was stunningly stopped in the 10th round of an upset. Matthysse suffered an eye injury and broken orbit bone that kept him sidelined until he made a triumphant return on May 6. Moving up in weight, Matthysse looked very sharp in taking apart Emanuel Taylor in a fifth-round knockout win on the Canelo Alvarez-Julio Cesar Chavez Jr. HBO PPV undercard in September. Matthysse will return in early 2018 to face Thailand's Tewa Kiram (38-0) for a secondary world title on HBO.
Next: Jan. 27 vs. Kiram