Shaughnessy playoff

The Shaughnessy playoff system is a method of determining the champion of a sports league that is not in a divisional alignment. This format is also known as the Argus finals system. It involves the participation of the top four teams in the league standings in a single elimination tournament. While the first round of the playoffs involve the pairing of the first- and fourth-place teams in one contest (whether it be a single game or a series of games) and the second- and third-place teams in the other, a variant of the Shaughnessy playoffs would pair the first- and third-place teams in one semifinal round and the second- and fourth-place teams in the other. In either variant, the winners of the first two games would then compete for the league championship. Some lower-level leagues use a Shaughnessy playoff for purposes of promotion to the next-higher league.

Another variant of the Shaughnessy system exempts a certain number of top teams from the playoffs (usually one to three teams) and instead involves the next four teams in the league standings. This variation is almost always used by a lower-level league for promotion purposes. Typically, the exempted top finishers earn automatic promotion and the playoffs determine the final promotion place.

The Shaughnessy playoff system was invented in 1933 by Frank Shaughnessy, the general manager of the Montreal Royals minor league baseball team of the International League. After its successful implementation by the International League, the popularity of the new postseason format spread to other leagues in other sports, including the All-America Football Conference (which used the Shaughnessy playoff system in the league's last season of existence) and the minor American football league American Association, which used the format in five of its championship seasons. The format has also been widely used in minor league baseball on all levels.

In the Original Six era of the National Hockey League (1942-1967), the circuit adopted a Shaughnessy playoff system (first place vs. third place and second place vs. fourth place) in which the paired teams played in a best-four-of-seven-games series with the winners advancing to the Stanley Cup championship round.

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