Has Any Team Gone Undefeated in the Playoffs?

Whether a team has gone undefeated in the playoffs depends entirely on the sport. In single-elimination playoffs, the NFL and the college tournaments, every champion is undefeated in the playoffs by definition, because one loss ends your season. The real question is the best-of-seven leagues, and there the answer is stricter: under today’s expanded formats, no NBA, NHL or MLB champion has swept every round.

It has happened, but only under older, shorter playoff formats. Two teams stand out: the 1952 Detroit Red Wings, who went 8-0, and the 1976 Cincinnati Reds, who went 7-0. Both did it when the playoffs had just two rounds. Here is how the question changes sport by sport, and why the modern game has made a perfect run nearly impossible.

Undefeated playoff runs by sport

The table shows how the answer differs depending on the playoff format, and the closest each league has come.

Sport	Format	Perfect playoff run?
NFL	Single elimination	Every champion, automatically
MLB	Best-of series	1976 Reds, 7-0 (old two-round format)
NHL	Best-of-seven	1952 Red Wings, 8-0 (old two-round format)
NBA	Best-of-seven	Never; closest 2017 Warriors, 16-1

The split is clean. Where one loss ends your run, going undefeated is the only way to win, so it is common. Where you play series and can lose games while still winning the title, a perfect run is a genuine rarity that the modern, longer bracket has all but ruled out.

The NFL: undefeated in the playoffs by default

In the NFL, asking whether a champion went undefeated in the playoffs answers itself. The playoffs are single elimination, so the team holding the trophy won every postseason game it played. That is true of every Super Bowl winner, which is why the interesting NFL question is a perfect regular season, not a perfect playoff run.

Only one NFL team has ever paired the two, going unbeaten in both the regular season and the playoffs. For that story, see our page on every undefeated NFL team, which covers the 1972 Dolphins and the near-misses. That record is about the full season; the playoff part is the easy half.

The best-of-seven leagues, where it almost never happens

Baseball, hockey and basketball are where “undefeated in the playoffs” becomes a real feat, because you can lose games and still win a series. Under modern formats, none have done it. The NBA’s best runs are the 2017 Warriors (16-1) and 2001 Lakers (15-1), each a single loss from perfection across four rounds.

The two teams that did run the table both benefited from a shorter bracket. The 1952 Red Wings swept two best-of-seven series to go 8-0, and the 1976 Reds swept the NLCS and World Series to go 7-0. Neither faced the four-round gauntlet today’s champions must survive, which is exactly why their feats have not been repeated.

Why the modern bracket makes it so hard

The reason is simple arithmetic. More rounds mean more series, and each best-of-seven gives a good opponent several chances to steal one game. A perfect NBA or NHL run now means 16 straight wins; a perfect MLB run means sweeping three or four rounds. Across that many games against elite teams, avoiding a single bad night, key injury or hot goaltender is close to impossible.

That is why the closest modern teams all share the same profile: dominant, but with one loss they could not avoid. The format, not the quality of the teams, is what keeps the perfect postseason out of reach.

If you enjoy the idea of a run that survives only while you keep winning, our 98-0 game turns a perfect streak into a challenge, where one wrong answer does what a single playoff loss does to a real contender.

The short version: in single-elimination sports every champion is undefeated in the playoffs, but in the best-of-seven leagues only the 1952 Red Wings and 1976 Reds ever swept every round, and the modern, longer bracket has kept anyone from joining them.