The consensus pound-for-pound greatest of all time is Sugar Ray Robinson (1921-1989). He won welterweight and middleweight world titles, finished welterweight 91-0 against world-class opposition, and held the middleweight title five separate times. The Ring magazine, the BWAA, and almost every credible historian places Robinson at #1. The runners-up — Henry Armstrong, Muhammad Ali, Joe Louis, Floyd Mayweather, Sugar Ray Leonard — are arrangeable but Robinson is fixed at the top.

There are 17 modern professional weight classes recognised by the four major sanctioning bodies, from minimumweight (105 lb / 47.6 kg) to heavyweight (no upper limit). The WBC introduced a 224-pound "bridgerweight" class in 2020 but it is not yet broadly recognised by the WBA, IBF, or WBO. See the full list on our weight-classes page.

The four major bodies are the World Boxing Association (WBA, 1921), the World Boxing Council (WBC, 1963), the International Boxing Federation (IBF, 1983), and the World Boxing Organization (WBO, 1988). All four are recognised as equivalent for unification purposes since 2007. The Ring magazine title (1922) is sometimes counted as a fifth — but as a 'lineal' championship recognised by tradition, not a formal sanctioning belt.

An undisputed champion holds all four major belts simultaneously (WBA, WBC, IBF, WBO). The first undisputed four-belt male champion was Terence Crawford at super lightweight (August 2017). Since then, fighters like Oleksandr Usyk (cruiserweight, then heavyweight), Naoya Inoue (bantamweight + super bantamweight), Canelo Álvarez (super middleweight), Devin Haney (lightweight), Claressa Shields (middleweight, super middleweight, light heavyweight), and Katie Taylor (lightweight, super lightweight) have all achieved undisputed status.

A KO (knockout) happens when a fighter is knocked down and cannot rise from the canvas within the referee's 10-second count. A TKO (technical knockout) is when the fight is stopped by the referee, ringside doctor, or the fighter's own corner because the fighter can no longer intelligently defend themselves — but they may still be on their feet. In statistical records, both count as a stoppage win.

Professional boxing uses the "10-9 must" system. The judge gives the round winner 10 points and the loser 9 points. A knockdown deducts 1 additional point (10-8 round). Two knockdowns make a 10-7 round; three a 10-6. Effective aggression, ring generalship, defence, and clean punching are the four scoring criteria. Three judges score independently and the majority opinion decides the bout.

Championship bouts are 12 rounds of 3 minutes each, with 1-minute rest periods between rounds. Non-title professional bouts vary from 4 to 10 rounds. Until 1988 championship fights were 15 rounds — shortened after Duk Koo Kim's death in his 1982 fight with Ray Mancini and concerns about late-round head trauma.

When a boxer is knocked down (any part of the body other than the feet touches the canvas), the referee starts a 10-second count. If the fighter rises and indicates they can continue before the count reaches 10, the bout resumes. If not, it's a KO. In some jurisdictions the standing 8-count adds a forced 8-second pause when a fighter is hurt but not down.

Find a reputable boxing gym in your area. Start with the basics: stance, jab, and footwork — typically 4-6 weeks of fundamentals before adding power punches. Buy hand wraps and 16-oz gloves (sparring weight). Plan for 4 sessions per week minimum: 2-3 gym sessions plus 2-3 roadwork (running) sessions. After 6 months, light sparring with a coach. Read our 8-week beginner program for a complete plan.

A southpaw is a left-handed boxer who fights from the right-foot-forward stance — the mirror image of the orthodox stance. Famous southpaws include Manny Pacquiao, Vasiliy Lomachenko, Naoya Inoue (although he is naturally right-handed and fights orthodox), Gervonta Davis, and historically Marvelous Marvin Hagler (who was a switch-hitter but fought predominantly southpaw).

Each sanctioning body ranks the top 15 contenders per weight class. The #1 contender is the 'mandatory challenger' — the boxer the champion is required to face within a defined window (typically 9-15 months). If the champion ducks the mandatory, the body can strip them of the belt. The mandatory system is the source of most title vacancies in modern boxing.

The lineal champion is the boxer who beat 'the man who beat the man' — a title traced back through head-to-head wins to the original holder. The lineal title is recognised independently of sanctioning-body politics. The Ring magazine title often coincides with the lineal title but not always. The lineal title can only be lost in the ring (or in retirement) — never by vacation.

Boxers gradually drop weight over a 6-12 week fight camp (typically losing 1 lb per week). The final 3-5 lbs come off in the last 7 days through water-loading, sodium manipulation, and carb depletion. After weigh-in (typically 24-30 hours before fight night), they rehydrate intensively. Excessive cuts are dangerous and increase brain-injury risk; the WBC's day-of-fight weigh-in is designed to limit rehydration to 10 lbs.

In theory, four major belts plus The Ring magazine title in a single division — what we call 'undisputed plus Ring' status. In practice some fighters add interim and 'super' designations beyond the regular belts. The WBA has historically recognised as many as 4 belt-holders per division (Super, Regular, Interim, Gold) — a practice the body has been trying to consolidate since 2021.

Floyd Mayweather Jr. vs. Manny Pacquiao on May 2, 2015 at the MGM Grand Garden Arena in Las Vegas. Approximately 4.6 million PPV buys, ~$700 million gross revenue (between PPV, live gate, sponsorships, foreign broadcasting). Mayweather won by unanimous decision. The runner-up is Mayweather vs. Conor McGregor (August 2017), then Tyson Fury vs. Deontay Wilder II (February 2020).

Yes. Amateurs fight 3 rounds of 3 minutes (4 x 2 minutes for women), wear headgear (in some events), use 10-oz gloves, and are scored on punch count more than damage. Professionals fight 4-12 rounds without headgear, use 8-10 oz gloves (welter and below) or 10-12 oz (above welter), and are scored on a more subjective 10-9 must system. The Olympic format has shifted between AOB (computer scoring) and traditional 10-point-must scoring over the decades.