The three division winners and the non-division winner with the best record are seeded 1 through 4 for the playoffs in order of their records, with all remaining non-division winners seeded 5 through 8. This leaves open the possibility that a #2 or #3 seed could be a non-division winner. Home-court advantage in a playoff series is decided by record, not by seeding, so if the #4 and #5 teams meet in a playoff series in which the #5 team has the better record, the #5 team would have home-court advantage.
The reasoning behind this seeding arrangement is that a non-division winner could have a better record than the winners of the two divisions other than the non-division winning team in question. If the three division winners were seeded 1 through 3 for the playoffs in order of their records, and all non-division winners seeded 4 through 8, it would be possible for the two best teams of the conference to meet in the Conference Semifinals. This actually happened in the 2006 NBA Playoffs when the two best teams in the Western Conference, the San Antonio Spurs and the Dallas Mavericks, both from the Southwest Division, faced one another in the Western Conference Semifinals while the 3rd seed, the Northwest Division-leading Denver Nuggets, had fewer wins than the 4th, 5th, 6th, and 7th seeds.The NBA proposed and approved of the current format to ensure that the best two teams of a conference can meet no earlier than the Conference Finals.
The Eastern Conference playoffs are divided into two preliminary rounds followed by the Eastern Conference Finals, with the winner of the Conference Championship facing the Western Conference champion in the NBA Finals to determine the champion. All playoff series are best-of-seven.
The current divisional alignment was adopted at the start of the 2004–05 season, when the Charlotte Bobcats began play as the NBA's 30th franchise. This necessitated the move of the New Orleans Hornets from the Eastern Conference's Central Division to the newly created Southwest Division of the Western Conference.