<P> Often, when a best - of - series tied with each team having won an even number of games, the bracket is said to be a "best - of - (number of games left)." This is because for all practical purposes the teams are starting over . If a best - of - 7 series is deadlocked at 2 - 2, the bracket is then referred to as a "best - of - 3", since the reality is that the first team to win 2 games advances . </P> <P> In tennis, matches are usually decided with a best - of - 3 - sets format . Some major tournaments are played in a best - of - 5 - sets format, most notably the Grand Slam men's singles and doubles . Also, the 35 and over Gentlemen's Invitation Doubles and the 35 and over Ladies' Invitation Doubles of the Wimbledon are both round - robin tournaments . </P> <P> The first use of the best - of - three playoff was in Major League Baseball; the National League authorised such a playoff to be held if two teams ended the season in a tie for first place; the American League used a single game in this situation . Since 1969 both leagues have used only a one - game playoff for all playoff positions which are tied if only one team can advance to the playoffs . Since 1995, a tie - breaker based on season performance can be used only to seed teams . </P> <P> Both the NBA and NHL once used best - of - three playoffs (often referred to as "mini-series"), but today neither league does: Pro basketball first adopted the best - of - three playoff for first - round play starting with its inception as the Basketball Association of America in 1946 (changing its name to the NBA three years later) and retaining it through the 1959--60 season; the league resumed its use of the best - of - three first - round series in 1974--75, but abolished it again in 1983--84 when the number of teams qualifying for its postseason tournament was increased to 16 (ten teams had qualified during the first two years of the aforementioned period, this number being expanded to twelve in 1976--77; in both instances some of the highest - ranking teams did not participate in the best - of - three round, drawing byes and automatically advancing to the second round, which was best - of - seven, as were all subsequent rounds). </P>

How many games are in the mlb playoff