Making the Playoffs Is Hard. Doing It Every Year Is Harder.

When the Phoenix Mercury lost to the Dallas Wings on Sunday, it ended an impressive period of sustained success. After a league-leading 10-year streak, the team will not be making the W.N.B.A. playoffs this season.

Being good enough to make the playoffs year after year is surprisingly difficult in sports. Player turnover, coaching changes or injuries, or all three, can lead to a losing record and a postseason on the sideline. Even with expanded playoff fields in many sports, a decade-long run like the Mercury’s is rare in the modern game.

Here’s a look at the current teams around North America that have been consistently good enough for the most seasons.

N.H.L.: Boston Bruins and Toronto Maple Leafs, 7

Full credit to the Bruins and Leafs for their current seven-season runs. Neither streak includes a Stanley Cup though. The Bruins last lifted the Cup in 2011 and the Leafs in … looking … looking … 1967.

But the most impressive recent playoff streak in hockey goes to the Pittsburgh Penguins, who made it 16 straight times, winning Cups in 2009, 2016 and 2017. Last season, the team missed the playoffs by a point to end that run.

W.N.B.A.: Connecticut Sun, 7

For the Mercury, the 10-year streak coincided with the arrival of Brittney Griner, a first overall draft pick. For the Sun, the key was starting Jonquel Jones, who had been a substitute in her rookie year. She scored 15 points a game and averaged a W.N.B.A.-record 12 rebounds a game in the 2017 season to take the Sun back to the playoffs.

The team has not missed since, including this season, its first after trading Jones to the Liberty. The team has two finals appearances, but no titles, during the streak.

N.F.L.: Kansas City Chiefs, 8

Say what you will about Andy Reid, but he has led Kansas City to the playoffs eight straight times. How hard is that? The next-best streak is four, by the Buffalo Bills. The Tampa Bay Buccaneers have three, three teams have two, and the streaks of the other 26 teams are at one or zero.

While Reid has had Patrick Mahomes as his starting quarterback for the past five seasons, the streak also includes three seasons with Alex Smith as the starter. It also includes three Super Bowl appearances in the last four seasons and two wins.

N.B.A.: Boston Celtics, 9

The Celtics, who made 19 straight playoff appearances in the 1950s and ’60s, and 14 more in the ’80s and early ’90s, are back on top now as well with a more modest streak.

That run has included a consistent core: six seasons of Jayson Tatum, seven of Al Horford and Jaylen Brown and nine of Marcus Smart. It has also included an N.B.A. finals appearance in 2022, a loss to the Golden State Warriors.

The Celtics have a long way to go to match the most impressive recent playoff streak in sports. The San Antonio Spurs made the playoffs in 22 straight seasons before missing the last three times. A new streak could well be starting next season though, with the arrival of the No. 1 overall pick, Victor Wembanyama.

Colleges are a different matter, of course, but that makes it no less impressive that Kansas’ men’s team has made 33 consecutive N.C.A.A. tournaments. And Tennessee’s women’s team has made every N.C.A.A. tournament that has ever been held — 41 of them.

M.L.B.: Los Angeles Dodgers, 10

This streak is soon going to be 11, barring an epic collapse. The Dodgers lead the National League West by 12 games, though they haven’t technically clinched a playoff spot.

The run includes back-to-back World Series losses, to the Houston Astros and the Boston Red Sox in 2017 and 2018, and a championship in 2020, albeit one that was played out in a Covid bubble in Arlington, Texas.

Stalwart hitters for the team have been Justin Turner (156 homers, 2014 to 2022) and Corey Seager (.504 slugging, 2015 to 2021), yet with both players gone this season, the team is still among baseball’s best.

The player most identified with the modern Dodgers, going back not just to the start of the streak in 2013 but all the way to 2010 when he was 20 years old, is starter Clayton Kershaw. He has 208 regular-season wins with the team plus 13 in the playoffs and three in the World Series, two of them in the 2020 victory.

M.L.S.: New York Red Bulls, 13

Here’s a chance to stump your friends: What major professional team has the longest active playoff streak? It is unlikely they will come up with the Red Bulls.

The answer seems surprising because the Red Bulls have been around since the inaugural season of M.L.S., 1996, when they were the MetroStars, and have yet to win an M.L.S. Cup, which goes to the playoffs’ winner. The best they have done during their current 13-season streak is reach the semifinals, which they have done three times.

This season, with nine teams from each conference making the playoffs, the Red Bulls are currently 11th, three points out with nine games to play. So you might want to ask that trivia question quickly.