Check out my rankings within each division by clicking on the links below. If there is a lineal champion in the weight class he is ranked No. 1.
For a list of the current champions in all weight classes, click here.
Note: Results through Oct. 17. 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
FEATHERWEIGHT DIVISION (UP TO 126 POUNDS)
1. Leo Santa Cruz (34-1-1)
Santa Cruz, a former bantamweight titlist and junior featherweight titlist, claimed a vacant featherweight belt in August 2015 as he outpointed Los Angeles rival Abner Mares in a much-anticipated fight that lived up to its hype. Santa Cruz, who went on to split a pair of outstanding title fights with Carl Frampton, was supposed next face Mares in a mandatory rematch Oct. 7 on Showtime, but the deal fell apart and they instead faced separate opponents on the same Oct. 14 Fox card. Santa Cruz hammered wildly undeserving title challenger Chris Avalos in an eighth-round knockout to set up the rematch with Mares, who also won, in March.
Next: TBA vs. Mares
2. Carl Frampton (23-1)
Northern Ireland's Frampton was the consensus 2016 fighter of the year after unifying junior featherweight world titles against British rival Scott Quigg and then moving up in weight to outpoint Leo Santa Cruz in a fantastic fight as he claimed a featherweight title to become the first fighter from his country to win titles in two weight classes. Frampton and Santa Cruz met again in the much-anticipated rematch on Jan. 28 and produced another outstanding fight, but this time Santa Cruz got the nod by majority decision. Frampton's return on July 29 in a Belfast homecoming fight against Mexico's Andres Gutierrez was canceled the day before when Gutierrez slipped in the shower, suffered cuts and two chipped teeth and the fight was canceled. Not long after, Frampton cut ties with longtime manager Barry McGuigan and Cyclone Promotions and signed with Frank Warren, for whom he will have his first fight in Belfast against Mexico's Horacio Garcia (33-3-1).
Next: Nov. 18 vs. Garcia
3. Abner Mares (31-2-1)
Mares, who has won world titles in three weight classes, dropped a majority decision to Leo Santa Cruz for a vacant title in a terrific fight in August 2015. After a 16-month layoff because of two fight postponements, Mares returned to outpoint Argentina's hard-charging Jesus Cuellar and take his belt on Dec. 10 in an excellent fight that featured Mares scoring an 11th-round knockdown and outboxing the stronger Cuellar. Next up Mares was supposed to get his rematch with Santa Cruz on Oct. 7 on Showtime, but Santa Cruz's side insisted on an interim bout first. So he and Mares both fought and won on the same Oct. 14 Fox card with Mares punishing Andres Gutierrez in a one-sided 10th-round technical decision victory. Now Mares will get his rematch with Santa Cruz in March.
Next: TBA vs. Santa Cruz.
4. Oscar Valdez (23-0)
Valdez, Mexico's only two-time Olympic boxer, made his second title defense against mandatory challenger Miguel Marriaga, a tremendous puncher from Colombia, in the main event of an April 22 Top Rank PPV card. It was a terrific fight against a quality opponent. Valdez scored a 10th-round knockdown and won by unanimous decision. Then Valdez headlined a Top Rank ESPN card in his boyhood home of Tucson, Arizona, on Sept. 29 and exchanged knockdowns with the Philippines' Genesis Servania en route to another decision victory in yet another terrific action fight.
5. Gary Russell Jr. (28-1)
In June 2014, Vasyl Lomachenko dominated Russell in their fight for a vacant title. After Russell rebounded with a tuneup victory, he challenged Jhonny Gonzalez for his belt in March 2015 and was brilliant. Russell, whose hands might be the fastest in boxing, crushed Gonzalez, dropping him three times en route to a fourth-round knockout victory to win the belt. After 13 months out of the ring, in part because of a cut, Russell returned for his first defense April 16 and smashed Patrick Hyland, whose presence in a world title bout was mystifying. Russell dropped him three times in a second-round knockout. In defense No. 2, Russell looked tremendous in a one-sided seventh-round knockout of interim titlist and mandatory challenger Oscar Escandon on May 20.
6. Lee Selby (25-1)
Wales' Selby was scheduled to make his mandatory defense against former titlist Jonathan Victor Barros of Argentina, on Jan. 28 on the Carl Frampton-Leo Santa Cruz II undercard, hoping a win would set him up for a unification fight with the main event winner. However, the fight was canceled at the weigh-in because Barros came up positive for hepatitis in his medical exam. With his mandatory defense in limbo, Selby returned in a nontitle junior lightweight bout against Spain's Andoni Gago on March 4 and won by ninth-round knockout on the David Haye-Tony Bellew undercard. The fight with Barros was rescheduled for July 15 in London on the Chris Eubank Jr.-Arthur Abraham undercard and Selby cruised to a lopsided unanimous decision under difficult circumstances: His mother died a few days before the fight.
7. Jesus Cuellar (28-2)
Argentine slugger Cuellar made his second defense in December 2015 against Puerto Rico's Jonathan Oquendo, whom Cuellar easily outpointed in a snoozer because Oquendo ran for most of the fight. His third defense, against Abner Mares, was scheduled for June but postponed until Dec. 10, when Cuellar got dropped by Mares in the 11th round and lost a split decision and his belt.
8. Nonito Donaire (38-4)
"The Filipino Flash" lost his junior featherweight title to Jessie Magdaleno in an outstanding fight in November 2016 on the Manny Pacquiao-Jessie Vargas undercard, but Magdaleno refused to give him a rematch and Donaire sought, and received, an early release from his Top Rank promotional contract. He signed with promoter Richard Schaefer's Ringstar Sports and moved back up to featherweight, where he once held a world title, and outpointed Mexico's Ruben Garcia Hernandez in San Antonio on Sept. 23.
9. Scott Quigg (33-1-2)
England's Quigg suffered a broken jaw and lost his junior featherweight belt to Carl Frampton by split decision in their huge unification fight in February 2016. Returning from the injury on Dec. 10, and moving up in weight, Quigg scored a sensational ninth-round knockout of Mexico's Jose Cayetano to announce his arrival at 126 pounds. Quigg, in his first fight with trainer Freddie Roach after parting ways with Joe Gallagher, returned April 29 on the Anthony Joshua-Wladimir Klitschko undercard and claimed a hard-fought unanimous decision against Romania's Viorel Simion in an eliminator. He will stay busy in Monte Carlo by taking on Ukraine's tough Oleg Yefimovich (29-2-1).
Next: Nov. 4 vs. Yefimovich
10. Jesus Rojas (26-1-2)
In the main event of a "Golden Boy Boxing on ESPN" card on Sept. 15, Puerto Rico's Rojas knocked out the Dominican Republic's slick Claudio Marrero with a great left hook in the seventh round to win an interim world title in an excellent fight.