Sport includes all forms of competitive physical activity or games which, through casual or organised participation, aim to use, maintain or improve physical ability and skills while providing enjoyment to participants, and in some cases, entertainment for spectators. Usually the contest or game is between two sides, each attempting to exceed the other. Some sports allow a tie game; others provide tie-breaking methods, to ensure one winner and one loser. A number of such two-sided contests may be arranged in a tournament producing a champion. Many sports leagues make an annual champion by arranging games in a regular sports season, followed in some cases by playoffs. Hundreds of sports exist, from those between single contestants, through to those with hundreds of simultaneous participants, either in teams or competing as individuals. In certain sports such as racing, many contestants may compete, each against each other, with one winner.
Sport is generally recognised as system of activities which are based in physical athleticism or physical dexterity, with the largest major competitions such as the Olympic Games admitting only sports meeting this definition, and other organisations such as the Council of Europe using definitions precluding activities without a physical element from classification as sports. However, a number of competitive, but non-physical, activities claim recognition as mind sports. The International Olympic Committee (through ARISF) recognises both chess and bridge as bona fide sports, and SportAccord, the international sports federation association, recognises five non-physical sports: bridge, chess, draughts (checkers), Go and xiangqi, and limits the number of mind games which can be admitted as sports.
Sports are usually governed by a set of rules or customs, which serve to ensure fair competition, and allow consistent adjudication of the winner. Winning can be determined by physical events such as scoring goals or crossing a line first. It can also be determined by judges who are scoring elements of the sporting performance, including objective or subjective measures such as technical performance or artistic impression.
Records of performance are often kept, and for popular sports, this information may be widely announced or reported in sport news. Sport is also a major source of entertainment for non-participants, with spectator sport drawing large crowds to sport venues, and reaching wider audiences through broadcasting. Sports betting is in some cases severely regulated, and in some cases is central to the sport.
Other bodies advocate widening the definition of sport to include all physical activity. For instance, the Council of Europe include all forms of physical exercise, including those competed just for fun.
In order to widen participation, and reduce the impact of losing on less able participants, there has been an introduction of non-competitive physical activity to traditionally competitive events such as school sports days, although moves like this are often controversial.
In competitive events, participants are graded or classified based on their "result" and often divided into groups of comparable performance, (e.g. gender, weight and age). The measurement of the result may be objective or subjective, and corrected with "handicaps" or penalties. In a race, for example, the time to complete the course is an objective measurement. In gymnastics or diving the result is decided by a panel of judges, and therefore subjective. There are many shades of judging between boxing and mixed martial arts, where victory is assigned by judges if neither competitor has lost at the end of the match time.
Sports have been increasingly organised and regulated from the time of the ancient Olympics up to the present century. Industrialisation has brought increased leisure time, letting people attend and follow spectator sports and participate in athletic activities.