Season (sports)

In an organized sports league, a season is the portion of one year in which regulated games of the sport are in session. For example, in Major League Baseball, one season lasts approximately from April 1 to October 1; in Association football, it is generally from August until May (although in some countries, especially those in Scandinavia and North America, the season starts in the spring and finishes in the autumn, due either to weather conditions encountered during the winter or to limit conflict with locally more popular football codes). A year can often be broken up into several distinct sections (sometimes themselves called seasons). These are:

Preseason
Most team sports have a period of training to recover fitness levels, followed by exhibition games (commonly known as "friendlies" in football (soccer) lexicon) prior to the start of their regular seasons ("pre-season training" and "pre-season" games). The game results do not count in the season standings of the teams, so they serve conveniently to test player candidates and to practice teamwork under game conditions. They may be used to promote the team effectively both at home and elsewhere. For some teams a pre-season overseas tour may be profitable, even lucrative. For some leagues, overseas games may promote their sport or their league to new audiences.

In some sports there may be a pre-season curtain-raiser or "supercup" competition—for example, in England, the previous season's winners of the FA Cup and Premier League play one another for the Community Shield before the start of the regular season. Part of the profits from this game are divided up amongst all teams participating in both competitions the year before, to donate to charities and good causes in their local area while the rest is given to national charities and good causes by The FA itself.

Regular season
In almost every sport the term "regular season" would refer to the sport's league competition. In most countries the league is played in a double round-robin format, where every team plays every other team twice, once at their home venue, and once away at the oppositions venue as visitors. The results over all games are accumulated and when every team has completed its full schedule of games, a winner is declared.

In addition to the regular season league competition, many sports also operate an elimination cup tournament. A cup tournament can either take the form of a league cup, where members of a league competition are seeded using their standings from the previous year, or an association cup which is open to teams playing the sport at all levels providing they are affiliated to the National body for that sport. These competitions usually run alongside the regular league competitions, though often there is a small overlap where the cup either begins slightly before or ends slightly after the regular season. It is not uncommon for the cup final to be held the week after the last games of the league.

In such a set-up it is usual for the top division teams to be given a bye into the last few rounds while the smaller teams are randomly drawn against each other in the early rounds. This set-up allows for the possibility of relative minnows and small-town teams to become giant-killers and eliminate one of the big Nationally recognised clubs from the competition.

In North American, and some Australian sports, the cup tournament is held immediately after rather than during the regular season and using the seedings from it. Also, in these sports, the league champion is determined by the cup competition, known as playoffs in North America and "finals" in Australia. In all four major US sports, winning the cup final (Super Bowl, World Series, NBA Finals and Stanley Cup) is vastly more important than winning the league. Similarly, in most major Australian sports, winning the cup final, most often called a Grand Final (as in the AFL, NRL and A-League), is more important than winning the regular season. However, that country has a tradition of presenting special trophies to teams that top the regular-season table (called "minor premiers" in the AFL and NRL, and "premiers" in the A-League). Leagues that play sports that primarily developed in North America such as Japanese professional baseball and professional baseball is organized similarly, while sports that developed primarily in Europe such as top flight of association football uses the traditional European double round-robin format with no playoffs.

In North America, this may be in part due to the unusual way in which that region's sports leagues are scheduled. Rather than every team playing all others twice, teams may play more games against local rivals than teams in other parts of the country. For example, the NBA's Los Angeles Lakers will play the Los Angeles Clippers (a team within their division, a sub division of the conference)four times in a regular season, while both will only play the Boston Celtics, who are in the opposite Eastern Conference, twice. Part of this is due to the vast geographic distances between some teams in North America - measured in a straight line Los Angeles is 2,606 miles (4,194 kilometers) from Boston, for instance - and a desire to limit travel expenses. In the scheduling system used in the NFL, it is possible for two teams to only meet every four years. Major League Baseball has the most uneven schedules of all the four major North American sports. In MLB the conferences are called leagues instead, but have exactly the same effect as conferences (as with all North American sports leagues, leagues, conferences and division are not based on skill, but instead geography, history and rivalries). Teams play 19 games against each of teams in their own division each year but will only play 18 games total against all of the teams in the other league. Because each of the interleague matchups is part of a 3-game series, teams will play no games at all against most teams from the other league.

In Australia, the two largest football leagues, the AFL (Australian rules football) and NRL (rugby league), both grew out of competitions held within a single city (respectively Melbourne and Sydney) and only began expanding to the rest of the country when inexpensive air travel made a national league possible. These leagues use a single table instead of being split into divisions.

Many association football leagues in Latin America have a very different system. Because most Latin American countries never had a football cup competition, they instead split their season into two parts, typically known as the Apertura and Clausura (Spanish for "opening" and "closing"). Most countries that use this system, Argentina being one notable example, crown separate league champions for each part of the season, using only league play. A few others, such as Uruguay, crown one champion at the end of a playoff involving top teams from each half of the season. Mexico operates its Apertura and Clausura as separate competitions that both end in playoffs.

A system similar to the Apertura and Clausura developed independently in Philippine professional basketball, with formerly two, now three tournaments (called "conferences") in one season, with each conference divided into an "elimination round" (the regular season) and the playoffs in the North American sense. Winning the playoffs is the ultimate goal of every team for every conference; while there is no season championship, winning all conferences within a single season is rare and has only happened four times 1975, and has not happened since 1996. The elimination round and playoffs setup has permeated down to the local level and in most team sports, although seasons are not divided into conferences.

Postseason
Many sports leagues have playoffs that occur after the regular season is complete. A subset of the teams enter into a playoff tournament, generally a pre-determined number with better overall records (more wins, fewer losses) during the regular season. There are many variations used to determine the champion, the league's top prize.

European leagues have also started holding playoffs (called "play-offs") after a double round-robin "regular season". The Football League started its promotion play-offs in 1987, with the third up to the sixth-ranked teams participating for the final promotion berth (the two top teams are automatically promoted). Elsewhere, relegation playoffs are also held to determine which teams would be relegated to the lower leagues. One prominent top-level association football league, the Eredivisie of the Netherlands, uses two different playoffs—one for relegation purposes, and the other to determine one of the league's entrants in the following season's UEFA Europa League. In Superleague Greece, which currently has two places in the UEFA Champions League and three in the Europa League, the teams that finish second through fifth in the regular season enter a home-and-away "playoff" mini-league that determines the country's second Champions League place, and the points at which the other three teams enter the Europa League.

Although rugby union did not become professional until 1995, that sport has a long history of playoffs, primarily in France and the Southern Hemisphere. The French national championship, now known as Top 14, has conducted a championship final since its inception in 1892, and first used multiple rounds of playoffs in 1920. South Africa's Currie Cup has determined its champions by playoffs since 1968, and New Zealand's National Provincial Championship, the top level of which is now known as the ITM Cup, has used playoffs since its inception in 1976. Argentina's Nacional de Clubes has determined its champion by playoffs since its inception in 1993. Currently, two separate competitions feed into the Nacional, the Torneo de la URBA (for Buenos Aires clubs, held since 1899) and Torneo del Interior (for the rest of the country); both use playoffs to determine their champions. Super Rugby, involving regional franchises from Australia, New Zealand, and South Africa, has used playoffs to determine its champions since its creation as Super 12 in 1996.

By contrast, other European countries were slow to adopt playoffs in rugby union. The English Premiership only began playoffs in 1999–2000, and did not use them to determine the league champion until 2002-03. The Celtic League, now known as Pro12, resisted a playoff system even longer; its champions were determined solely by league play from its inception in 2001–02 until playoffs began in 2009–10.

When the UEFA Champions League reformatted in 1993, it added a "knockout stage" involving four teams that finished at the top two places in their respective groups. Like North American sports leagues, this setup prevented some participants from facing each other, necessitating a two-round knockout stage to determine the champions. It has since been expanded to the 4-round knockout stage today. The Copa Libertadores has applied a knockout stage since the 1988 tournament, expanding to the current four-round format next season. All intercontinental club football competitions now feature a knockout stage.

Off-season
The off-season, vacation time, or close season is the time of year when there is no official competition. Although upper management continues to work, the athletes will take much vacation time off. Also, various events such as drafts, transfers and important off-season free agent signings occur. Generally, most athletes stay in shape during the off-season in preparation for the next season. Certain new rules in the league may be made during this time, and will become enforced during the next regular season.

As most countries which have a league in a particular sport will operate their regular season at roughly the same time as the others, international tournaments may be arranged during the off season.

For example, most European football league club competitions run from July or August to May, subsequently major international competitions such as the FIFA World Cup and UEFA European Football Championship are organised to occur in June and July.

Seasons by league
The table represents typical seasons for some leagues by month. Blank or white denotes off-season and pre-season months and solid colors mark the rest of the year. Leagues in the same sport use the same color.
 * "Q" denotes pre-competition qualifiers
 * "S" denotes the start of the regular-season.
 * "P" denotes playoff(s)/postseason/knockout stages.
 * "F" denotes Final(s).