NBA playoffs

If two or more teams within the same conference are tied in overall winning percentage, tiebreaker criteria are used to determine final rankings.

The tiebreaker criteria are as follows:[3]

1. Head-to-head record; better record in games with the tied teams.
2. Division record; better record in games against teams in its own division (Only if the teams are in the same division).
3. Conference record; better record in games against teams in its own conference.
4. Winning percentage against playoff teams in its own conference.
5. Winning percentage against playoff teams in the opposing conference.
6. Point differential in all games.

Should three or more teams tie, any division leaders are given higher seeds regardless of any other criteria. In addition, once any team is eliminated from a tiebreaker, the evalation goes back to the first step for the remaining teams. Prior to 2016, this rule was also used for two-team ties, but only applied if the two teams have the same head-to-head record.[4]

The playoff format in place for the 2004–05 and 2005–06 NBA playoffs created controversy and would be changed prior to the 2006–07 NBA season.[7]

Prior to 2004, when the NBA was aligned into two conferences with two divisions each, the division champions were guaranteed the top two seeds. This meant that the top two teams in a conference could never meet until the conference finals, assuming they both made it to that round.

After the NBA realigned its two conferences into three divisions each, the seeding rules remained largely unchanged. The top three seeds would now be reserved for division champions. However, this meant that if the top two teams (by record) in a conference were in the same division, the division runner-up could do no better than the fourth seed. Assuming no first-round upsets, this raised the prospect that the top two teams in the conference would face each other in the conference semifinals, instead of the conference finals. In the second year of this format, the 2005–06 NBA season, the two teams with the best records in the Western Conference (and the second- and third-best records in the entire league), the San Antonio Spurs and Dallas Mavericks of the Southwest Division, did just that. This turn of events led to the playoff format being criticized by many.[7]

In August 2006, the NBA announced a rules change. Beginning in the 2006–07 season, the top four seeds in each conference would be seeded according to their win–loss totals. This assures that the team with the second-best record in the conference will receive the second seed even if it isn't a division champion, thus "guaranteeing that the top two teams in each conference cannot meet until the conference finals".[7]

• 1947: The playoffs were instituted with a three-stage tournament, similar to the Stanley Cup playoffs of the 1930s; the two first-place teams qualified directly to one semifinal where they played each other in a best-of-7 series. Teams finishing second & third qualified for the best-of-3 quarterfinals, where the two second-placed teams were paired in one quarterfinal, as were the two third-placed teams, and the two quarterfinal winners played each other in a best-of-three semifinal. The two semifinal winners played each other in the Basketball Association of America (BAA) best-of-7 final series.

There were no byes, or idle time, for the division champions – as there would be for higher-seeded playoff teams 1955–66 and 1975–83. All six 1947 participants played their first tournament games on Wednesday, April 2; in 1948 the two Eastern runners-up (E2, E3 in the figure) were idle for a few days only because there was a three-way Western tie to break. Both winners of the runners-up bracket, Philadelphia in 1947 and Baltimore in 1948, reached the final series having played fewer tournament games than their final opponents, Chicago in 1947 and Philadelphia in 1948, had played in the best-of-7 pairings of division champions. And both winners of the runners-up bracket won the final series. The "postseason" actually comprised 11 games played in a span of 21 days for the 1947 Chicago Stags and 13 games in 30 days for 1948 Philadelphia Warriors, the finalists who emerged from the pairing of division champions.[5]

• 1949: The playoffs were reorganized to match Eastern Division teams exclusively, and Western Division teams exclusively in two halves of the bracket. Thus the BAA tournament generated a playoff champion in each Division. (So did the NBA in each of three 1950 divisions, and so it has done in each half of the league since then.) The top four teams from each of the two divisions qualified. The quarterfinals and semifinals were renamed division semifinals and division finals, respectively, and both rounds were best-of-3. Thus, any playoff team might be eliminated in two games, one home game. The best-of-7 final was unchanged.

• 1950: The BAA was renamed as the National Basketball Association (NBA). With a three-division setup, 12 teams now qualified for the playoffs, with the top four teams from each division meeting in the best-of-3 division semifinals. The winners met in the best-of-3 division finals. With three teams remaining, the surviving team with the best regular season record qualified directly for the finals while the other two teams met in a best-of-3 NBA semifinals.

• 1951: With the NBA reverting to a two-division setup; the division semifinals reverted to its original 1949 format with only eight teams qualifying. The division finals was extended to a best-of-5 format.

• 1954: With only nine league members (soon to be eight), the number of playoff teams was cut down to six. The division semifinals was changed to a double round-robin format within the division, with the top three teams from each division qualifying (each team played four games). Following the round-robin games, the top two teams qualified for the best-of-three division finals, followed by the best-of-seven finals.

• 1955: The number of playoff teams remained at six, but the initial round-robin was dropped after one year in favor of giving the first-place team in each division a bye to the best-of-five division finals. Teams which placed second and third played a best-of-three division semifinal. In 1955 the byes provided five and six extra days idle for the first-place teams.[8]
• 1958: The division finals was extended to a best-of-seven format.
• 1961: The division semifinals were extended to a best-of-five format.

The 1961 to 1966 tournaments alone combined initial byes for the top seeded teams in each division with best-of-five initial series for second and third seeded teams in both divisions. The 1961 byes provided five and seven extra days idle for the first-place teams. By 1966 the schedule provided more rest for the first-round participants with byes of 11 and eight extra days idle.[9]

• 1967: The number of playoff teams was expanded to eight once more. The division semifinals now included the fourth-best team in each conference. The first-placed teams no longer received a bye. They were matched against the third-placed teams in the best-of-5 division semifinals, while the second-placed teams were now matched against the fourth-placed teams.
• 1968: The division semifinals was extended to a best-of-seven format.

• 1971: With an increased number of teams, the divisions were upgraded into conferences, which were then split into two divisions. Eight teams still qualified, four from each conference. Hence, the division semifinals and division finals came to be known as conference semifinals and conference finals, respectively. The top two teams in each division qualified as the Eastern Conference, comprising the Atlantic and Central divisions, while the Western Conference consisted of the Midwest and Pacific divisions. The first place team from one division would face the second place team of the other division within their conference. In the conference playoffs, a division winner always held home-court advantage over a second place team regardless of record.

• 1973: The playoff format was modified, as only the divisional champions qualified automatically; two wild-cards were also added from each conference. Once qualification was determined, the four qualifiers were seeded 1–4 based on record; divisional position no longer mattered. The No. 1 seed then played No. 4, and No. 2 played No. 3.

• 1975: The number of playoff teams was expanded from eight to ten. A first round was introduced which matched the fourth and fifth seeds in each conference in a best-of-3 first-round series, while the top three seeds received a bye. This is similar to the system currently used in the 2012 MLB postseason. Division winners did not automatically receive a bye to the Conference Semifinals.

• 1977: The number of playoff teams was expanded from 10 to 12. The first round now included the sixth best team in each conference, which was matched against the third seed. Only the division winners received byes to the next round.

The 1983 tournament is the latest to incorporate first-round byes for seeded teams. The first-round best-of-three series tapped off on Tuesday and Wednesday, April 19 and 20; the second-round best-of-sevens on Sunday to the following Wednesday, April 27. Counting from Tuesday the byes provided five to eight extra days idle.[10]

• 1984: The playoffs were expanded from 12 teams to 16 teams. All teams now participated in the first round, which was extended to a best-of-five series.

• 2003: The first round was extended to a best-of-seven series. This change arguably benefitted the higher seeds as it reduced the likelihood of an upset by a lower seed. It also meant that a team that swept their series 4–0 might have to wait up to two weeks to play their next series against a team that had won 4–3.

• 2005: Each conference was realigned into three divisions with each division winner qualifying for a top-three seed regardless of record. The next best five teams from each conference also qualify for the playoffs.

• 2007: To address the criticisms of having each division champion guaranteed a top-three seed, regardless of record, the rules were changed such that the division winners are now only guaranteed a top-four seed. The team with the second-best record in the conference is now guaranteed the second seed, even if it finishes second in its own division. This ensures that the two best teams in the conference will not meet until the conference finals at the earliest. The previous system raised the prospect of the two best teams in the conference being seeded 1 and 4 if they play in the same division, thus forcing them to play each other in the second round (given no upsets).
  • Note: In the example below, both the East's No. 2 seed and the West's No. 3 seed are not division champions.

• 2016: While the playoff bracketing did not change, qualification criteria were changed. The teams with the eight best records in each conference receive playoff berths, with no automatic berths or guaranteed top-four seed placement for division champions.
  • Note: In the example below, both the East's No. 7 seed and the West's No. 5 seed are division champions.

• 2020: Beginning in 2020, play-in games were used to determine the final qualified team(s) in the first round of the NBA playoffs.

In the 2020 play-in format, if the ninth-place team within a conference finished the regular season within four games of the eighth-place team, they would compete in a postseason play-in series.[11] This format was used only in the Western Conference, as the No. 9 Memphis Grizzlies finished within a half-game of the No. 8 Portland Trail Blazers.[12][13][14][15][16] Described as a best-of-two series, the Trail Blazers, needing only one win as the higher seed, eliminated the Grizzlies in game one to advance to the playoffs.[17]

• 2021: In 2021, the format for the play-in games was finalized.

In 2021, the top six teams in each conference advance to the playoffs, while seventh- through tenth-placed teams qualified for a play-in tournament. The seventh- and eighth-place teams got up to two chances to win one game to qualify for the playoffs, while the ninth- and tenth-place teams needed to win two consecutive games to advance.[18] The play-in games would become a permanent part of the postseason starting in 2023.[19]

W1 is Winner of 7/8 game
L1 is Loser of 7/8 game
W2 is Winner of 9/10 game
W3 is Winner of W2 / L1 game.