An athletic conference is a collection of sports teams, playing competitively against each other at the professional, collegiate, or high school level. In many cases conferences are subdivided into smaller divisions, with the best teams competing at successively higher levels. Conferences often, but not always, include teams from a common geographic region.
==United States and Canada==
In the United States and Canada, the National Hockey League (NHL) and National Basketball Association (NBA) are divided into the western (NHL, NBA) and eastern (NHL, NBA) conferences, with multiple divisions within each conference (three in each NBA conference, two in each NHL conference). In both leagues, a total of sixteen teams (eight from each conference) qualify for the leagues' postseason playoffs; division winners are guaranteed to qualify and are usually awarded the highest seeds, meaning they will generally have home-field advantage in a given round against a non-division-winner. Major League Soccer also divides itself into an Eastern and Western Conference, though it does not have divisions within them; it too allocates an equal number of teams from each conference to play for its MLS Cup Playoffs (for 2015, this will be six teams each).
The National Football League has an American Football Conference (AFC) and a National Football Conference (NFC). Both conferences have 16 teams, and each conference is divided into 4 divisions of 4 teams each. Each of the 4 division winners is guaranteed one of the top 4 seeds in the playoffs. These conferences, for the most part, derive from the fact that they were once separate organizations: the original National Football League and the 1960s American Football League; the two entities merged in 1970, with each league forming the basis of the NFC and AFC respectively.
Major League Baseball does not use the word "conference." Instead, it is divided into two separate leagues which are identical to the conferences listed above in all but name (which, although their operations have been integrated via the Commissioner of Baseball in modern times, were originally separately managed organizations with an intense rivalry). These are the American League and National League, with 15 teams each. Each league is divided into the Eastern, Central, and Western divisions, with all six divisions having 5 teams each. Each division winner is also guaranteed one of the top three seeds, even if their record is lower than the league's top wildcard team.
In all four sports, the champion of one conference (or league in MLB's case) plays the champion of the other conference for the final round championship, this is guaranteed to occur because the rules for the playoffs require play to be exclusively within the conference/league in all rounds before the final round, leaving only two teams for the finals (one from each conference/league) and the records of teams outside a conference/league are ignored, which can allow teams with inferior records to make the playoffs while teams in the other conference with better records do not get in. An extreme example of this occurred in the NFL in 2010 in regards to the Seattle Seahawks, who achieved a playoff position despite having a losing record of 7-9 (the only time this has happened in a non-strike season). In addition, teams' regular season schedules are weighted towards more games against other teams within their own division and to a lesser extent their own conference; NBA and NHL teams play at least one game against every other team in their league in a regular season, but in MLB and the NFL teams do not.
In college sports, the terms "league," "conference" and (generally at lower levels) "athletic association" can be used interchangeably to refer to a group of teams (generally eight to twelve colleges and/or universities, occasionally as high as sixteen) that regularly play against each other within a national governing body, the most significant of which is the National Collegiate Athletic Association (NCAA). Most of these groups (including the "Power Five" conferences that are primary partners in the College Football Playoff) refer to themselves as conferences, although the Horizon League, Ivy League, Patriot League, Pioneer League and Summit League use the word "league" instead, and another conference calls itself the Colonial Athletic Association. The NCAA itself is divided into divisions and subdivisions based on athletic scholarship eligibility, which can lead to redundancy when these conferences also have divisions of their own. For instance, the Southeastern Conference is part of NCAA Division I (specifically the Football Bowl Subdivision), but is itself also subdivided into an East and West division.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』