Professional boxing, or prizefighting, emerged in the early twentieth century as boxing gradually attained legitimacy and became a regulated, sanctioned sport. Professional boxing bouts are fought for a purse which is divided between the boxers as determined by contract. Most professional boxing bouts are supervised by a regulatory authority to guarantee the fighters’ safety. Most high-profile bouts obtain the endorsement of a sanctioning body, which awards championship belts, establishes rules, and assigns its own judges and referee. Professional boxing bouts are typically much longer than amateur bouts, and can last up to twelve rounds, though less significant fights can be as short as four rounds. Protective headgear is not permitted, and boxers are generally allowed to take substantial punishment before a fight is halted. Pro boxing has enjoyed a much higher profile than amateur boxing throughout the twentieth century and beyond.
Scoring: If a knockout or disqualification does not occur, the fight is determined by decision. In the early days of boxing, the referee decided the winner by raising his arm at the end of the bout, a practice that is still used for some pro boxing bouts in Britain. In the early twentieth century, it became common for the referee or judge to score bouts by the number of rounds won. To improve the reliability of scoring, two ringside judges were added besides the referee, and the winner was decided by majority decision. Since the late twentieth century, it has become common practice for all three judges to be ringside observers, though the referee still has the authority to stop a fight or deduct points.
At the end of the fight, the judges add their scores for all rounds, and each judge thereby determines a winner. If all three judges choose the same fighter as the winner, that fighter wins by unanimous decision. If two judges have one boxer winning the fight and the third judge scores it a draw, the boxer wins by majority decision. If two judges have one boxer winning the fight and the third judge has the other boxer winning, the first boxer wins by split decision. If one judge chooses one boxer as the winner, the second judge chooses the other boxer, and the third judge calls it a draw, then the bout is ruled a draw. The bout is also ruled a draw if at least two out of three judges score the fight a draw, regardless of the third score. In the United Kingdom, the bout is only scored by the referee, except when a title is at stake, in which case it is scored by three judges.
The most widely used scoring system since the mid-twentieth century is the “10-point must system”, so named because a judge “must” award ten points to at least one fighter each round (before deductions for fouls). Most rounds are scored 10-9, with 10 points for the fighter who won the round, and 9 points for the fighter the judge believes lost the round. If a round is judged to be even, it is scored 10-10. For each knockdown in a round, the judge deducts an additional point from the fighter knocked down, resulting in a 10-8 score if there is one knockdown or a 10-7 score if there are two knockdowns. If the referee instructs the judges to deduct a point for a foul, this deduction is applied after the preliminary computation. So, if a fighter wins a round, but is penalized for a foul, the score changes from 10-9 to 9-9. If that same fighter scored a knockdown in the round, the score would change from 10-8 in his favor to 9-8.
Other scoring systems have also been used in various locations, including the five-point must system (in which the winning fighter is awarded five points, the loser four or less), the one-point system (in which the winning fighter is awarded one or more points, and the losing fighter is awarded zero), and the rounds system which simply awards the round to the winning fighter. In the rounds system, the bout is won by the fighter determined to have won more rounds. This system often used a supplemental points system (generally the ten-point must) in the case of even rounds.
If a fight is stopped due to a cut from an unintentional headbutt, the fight goes to the scorecards only if a specified number of rounds (usually three, sometimes four) have been completed. Whoever is ahead on the scorecards wins by a technical decision. If the required number of rounds has not been completed, the fight is declared a technical draw or a no contest.
If a fight is stopped due to a cut resulting from a legal punch, the other participant is awarded a technical knockout win. For this reason, fighters often employ cutmen, whose job is to treat cuts between rounds so that the boxer is able to continue despite the cut.