Which Expansion Team Has Been the Best in MLB History?

Looking back into the history of MLB expansion, we rank each of the 14 expansion teams based on their success over the years.

HOUSTON, TEXAS - NOVEMBER 05: Yordan Alvarez #44 of the Houston Astros hits a three-run home run against the Philadelphia Phillies during the sixth inning in Game Six of the 2022 World Series at Minute Maid Park on November 05, 2022 in Houston, Texas. (Photo by Harry How/Getty Images)

Building up an expansion team takes a lot of work. It starts with a person or group that wins a bid for a city to bring in a new baseball franchise. They start from nothing; naming a team to find or build a stadium, building offices, hiring an entire front office and more extensive staff, and picking your players via an expansion draft and free agency. 

Expansion drafts can get crazy. Current teams can protect their best players but can’t protect everybody. Players like Gil Hodges, Trevor Hoffman, Bobby Abreu, Jeff Conine, and others all were drafted by expansion teams and went on to be well above average big leaguers and in some cases, Hall of Famers. 

However, those are needles in the haystack. It’s more common that teams get bottom-of-the-barrel players and end up in the division’s cellar for a while because of it. But with time, these teams can become some of the best in the game. 

Before we rank these expansion teams, how about a quick history lesson on how we now sit with 30 MLB teams? 

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History of MLB Expansion

1960 – The American League voted to expand to 10 teams. The Brooklyn Dodgers and New York Giants had already moved west, and due to that success, the American League added a new franchise, the Angels, in Los Angeles. 

The league also awarded a franchise to Minneapolis-St. Paul, but the owner of the Washington Senators asked to move the Senators there instead, leaving Washington to own the next expansion destination. 

This created three new teams in the American League. The Los Angeles Angels, the newly named Minnesota Twins from the Washington Senators, and now the new expansion team in Washington. 

1962 – The National League wasn’t about to let the American League take over, so they introduced two teams in 1962. Those two teams were the New York Mets and the Houston Colt 45s, now known as the Houston Astros. I like the team name Astros, but the Colts’ 45s might be the coolest name in professional sports. What a shame. 

1966 – The Athletics moved from Kansas City to Oakland

1967 – Both leagues voted to add two more teams for a total of 12 in each league.

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1968 – The Braves moved from Milwaukee to Atlanta, the first MLB team in the southeast.

1969 – Major League Baseball was expanding again. The Athletics’ move to Oakland expedited the expansion timetable. Instead of beginning play in 1971 as planned, we had 24 teams ready to take the field in 1969. 

Kansas City got a team back, the Kansas City Royals. Seattle got a team known as the Seattle Pilots, but that barely lasted, so they became the Milwaukee Brewers. 

The San Diego Padres were added in 1969 along with the Montreal Expos, becoming Canada’s first MLB franchise. 

Remember those Washington Senators? Instead of sticking in Washington, they were relocated to Texas and were named the Texas Rangers. 

1977 – The American League expanded from 12 to 14 teams, adding the Toronto Blue Jays and the Seattle Mariners. Canada gets another ballclub, and while the Pilots never made it off the ground, the Mariners certainly did. 

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1993 – The National League finally expands to 14 teams, adding the Colorado Rockies and the Florida Marlins. 

1998 – The year we landed on 30 teams. The Tampa Bay Rays went to the American League, and the Arizona Diamondbacks went to the National League. 

There have been movements and name changes through these 50 years of expansion in Major League Baseball. These rankings will be flawed, as we have to evaluate teams with wildly different records. We can look at the overall winning percentage, division titles, and World Series appearances and account for the difference in games played.

The 13 teams we will be evaluating and ranking since their inception are the Los Angeles Angels, New York Mets, Houston Astros, Milwaukee Brewers, Kansas City Royals, Florida Marlins, Toronto Blue Jays, Arizona Diamondbacks, Seattle Mariners, San Diego Padres, Montreal Expos/Washington Nationals, Tampa Bay Rays, Colorado Rockies. 

There are a few teams we discussed that are not technically expansion teams. The Athletics and Braves have just moved locations. The Rangers are technically the new Senators so they won’t be ranked here. Without further ado, here are the top 14 expansion teams since their conception. 

14. Seattle Mariners (.474) – 47 Seasons

5 Playoff Appearances, 0 Pennants, 0 World Series

Starting at the 14th spot is the Seattle Mariners. Before I did the research, there was no chance I would have guessed the Mariners would be at the bottom. But hey have the fourth-lowest winning percentage of all the expansion teams combined with no pennants or championships.

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They are the only expansion team without a pennant or a World Series, yet they’ve been around longer than teams like the Rockies. 

They did have one of the greatest regular seasons ever in 2001, going 116-46, but they lost in the ALCS. They have never even made it to game seven of the ALCS, let alone a World Series appearance. 

When choosing between 13 and 14 on this list, I had to ask myself, would I rather have one record-setting regular season or a World Series appearance? Give me the World Series. 

They’ve had great players, from Ken Griffey Jr. to Alex Rodriguez and Randy Johnson. However, they’ve never sustained any real success. 

12. Colorado Rockies (.469) – 31 seasons

5 Playoff Appearances, 1 Pennant, 0 World Series

Coming in at number 12 is the Colorado Rockies. They aren’t the team with the lowest winning percentage but rank 28th among the 30 current teams. The two teams lower than them will be discussed shortly, but they have been more successful in the playoffs than the Rockies. 

It’s challenging to build a winning ballclub when you play on the moon. The altitude persuades quality free-agent starting pitchers to stay away, and it makes it more challenging to develop starters when they are constantly shifting from their home environment back to sea level. 

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The Rockies have been to the playoffs five times in their 31 seasons. However, that is as many as the Mariners in 16 fewer seasons. They also made the World Series in 2007

The Rockies have had plenty of stars, highlighted by Todd Helton, Larry Walker, and Nolan Arenado. The stars often leave, and pitchers rarely succeed. Ubaldo Jimenez is their leader in WAR on the pitching side.

Remember when Ubaldo Jimenez went 15-1 before the All-Star break? What a time to be alive. 

11. San Diego Padres (.464) – 55 Seasons

7 Playoff Appearances, 2 Pennants, 0 World Series

No. 11 on our list is the San Diego Padres. They rank second to last in winning percentage, but they’ve been to the World Series twice.

You could argue for the last spot between these three teams, but the goal is to make the World Series, and the Padres have done it more than the other two teams. 

The 1998 Padres were loaded. Kevin Brown was arguably the best pitcher in baseball. Greg Vaughn, Andy Ashby, and Ken Caminiti were elite, and they had Trevor Hoffman put up a 1.48 ERA with 53 saves. They won 98 games that year and cruised to the World Series before facing one of the best teams of all time the 1998 Yankees.

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If they had faced anyone else, they would most likely have been crowned champions. 

San Diego has had great players, but 2007-2019 was a significant disappointment. A 12-year stretch as bad as that has to keep them near the bottom of this list. Things were looking up over the last five years, but San Diego doesn’t seem as sunny after trading Juan Soto. 

10. Miami Marlins (.460) – 31 Seasons

4 Playoff Appearances, 2 Pennants, 2 World Series

The Marlins come in at 10th on this list. As one of the newer expansion teams, only tallying 31 seasons, they had less time to be successful, but are the first team on the list with a World Series ring. Not just one, but two. 

The Florida Marlins were a lot more successful than the Miami Marlins. The winning percentage is 40 points higher, and both World Series rings came between 1993 and 2011 before the name change. 

It’s hard to decide which World Series team was better between 1997 and 2003. In 1997, the Marlins added established stars like Bobby Bonilla, Moises Alou, Cliff Floyd, and Alex Fernandez.

In 2003, the rookies established themselves in stardom. Both seasons had a magic to them, and both should be praised for their incredible runs. 

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The Marlins’ problem is they let all of their homegrowns stars. Players like Miguel Cabrera, Gary Sheffield, Hanley Ramirez, Christian Yelich, Giancarlo Stanton, JT Realmuto, and more found stardom with new teams. Even with these stars leaving, they’ve been competitive lately, making the playoffs twice in the last four seasons. 

9. Milwaukee Brewers (.484) – 55 Seasons

9 Playoff Appearances, 1 Pennant, 0 World Series

The Milwaukee Brewers hold the ninth spot on this list. Among these 14 expansion teams, they have the eighth-highest winning percentage, but no real playoff experience to hang their hats on. 

However, the 1982 Milwaukee Brewers were loaded. Paul Molitor and Robin Yount were the best-left sides of the infield ever. Gorman Thomas, Cecil Fielder, and Ben Ogilvie all had 32 home runs or more. Mike Caldwell and Pete Vuckovich posted ERAs under four while throwing 220+ innings each, and Hall-of-Famer Rollie Fingers had the closing duties. 

They had a 3-2 lead going into Game 6 of the World Series against the Cardinals before losing two straight. 

Since 2018, the Brewers have only missed the playoffs once. They constantly upset their fans with the lack of spending, but their ability to work with what they have should be praised.

The model is transparent for them, get in the playoffs and see what happens. They’ve been successful in doing that, but it hasn’t amounted to a ring in their franchise history. Among the teams mentioned so far, they are the best franchise of the last decade. 

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8. Montreal Expos/Washington Nationals (.485) – 55 Seasons

6 Playoff Appearances, 1 Pennant, 1 World Series

Coming in at number eight is the Montreal Expos/Washington Nationals. They have a slightly better winning percentage than the Brewers, and while they have fewer playoff appearances, they reached the pinnacle by winning a World Series in 2019. 

The Nationals have been far more successful than the Expos, with five of the six playoff appearances happening in Washington, along with the pennant and World Series ring. 

The 1994-1995 strike stopped what could have been a World Series ring for the Expos. They had the best record in Major League Baseball (74–40) when the strike ended the season prematurely.

That Expos team had four players with an OPS over .800, four pitchers with at least 20 starts and an ERA under 3.50. That rotation had a young Pedro Martinez who was scratching the surface of his fantastic career. 

This franchise has had some elite talent over the year as well. Some of the favorites are Vladimir Guerrero Jr, Juan Soto, Bryce Harper, Max Scherzer, Gary Carter, Stephen Strasburg, Larry Walker, and Pedro Martinez. 

The Nationals are rebuilding, but they’ll return in a few years. 

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7. Kansas City Royals (.478) – 55 Seasons

9 Playoff Appearances, 4 Pennants, 2 World Series

No. 7 on our list is the Kansas City Royals. Over 55 seasons, they have nine playoff appearances, four pennants, and two World Series titles. I know it hasn’t been pretty lately, but the Royals have a rich history of success. 

1976-1985, the Royals were perpetually in the World Series hunt. They went to three straight ALCS from 1976 to 1978. They lost in the World Series in 1980. Made the playoffs two more times and won a ring in 1985. 

George Brett was a monster in 1985, the pitching was elite behind starters Charlie Leibrandt and Bret Saberhagen, not to mention Dan Quisenberry closing out games. 

Now from those glory days int he 1980s, there was a bit of lull for the Royals until 2014. However, 2014-2015 was a mini-dynasty for the Royals, going to back-to-back World Series and coming out on top in 2015. 

George Brett is the name everyone knows, but players like Kevin Appier, Amos Otis, Willie Wilson, and Bret Saberhagen all posted War totals of over 40 in their careers with the Royals. 

Similarly to the Nationals, it’s been rough sledding recently, but with starts like Bobby Witt Jr, Vinnie Pasquantino., and Cole Ragans, the future looks promising in Kansas City. 

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6. New York Mets (.482) – 62 Seasons

10 Playoff Appearances, 5 Pennants, 2 World Series

At number six, we have the New York Mets. They certainly have accolades as one of the oldest teams on this list. Ten playoff appearances, five pennants, and two World Series rings. They sit with the ninth-lowest win percentage of this group, which makes sense. The Mets are generally on either side of the aisle, big-time contenders or spending time in the cellar. 

Who could forget the Miracle Mets of 1969? A rag-tag group of guys led by Tom Seaver and Cleon Jones.

The 1986 Mets team was the greatest team in their franchise history. Doc and Darryl were the rookie phenoms, but they were led by Hall-of-Fame caliber players like Gary Carter and Keith Hernandez.

The Mets have been up and down as a franchise but have been to the playoffs six times since 1999, including two World Series appearances. 

Great players have made Queens, NY their home, including Tom Seaver, David Wright, Doc Gooden, Darryl Strawberry, Jacob deGrom, Keith Hernandez, Gary Carter and Ed Cranepool.

With Steve Cohen at the helm, it’s almost guaranteed that the Mets will be competitive year in and year out basis with the highest payroll in baseball—time for Cohen to deliver on his promise of a World Series. 

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5. Los Angeles Angels (.498) – 63 Seasons

10 Playoff Appearances, 1 Pennant, 1 World Series

Coming in at number five is the Los Angeles Angels. They’ve had a few different names since their inception over 60 years ago. The club’s full name changed from the Los Angeles Angels to the California Angels in 1965 before becoming the Anaheim Angels in 1997.

Owner Arte Moreno changed the name to the Los Angeles Angels of Anaheim in 2005, and the club dropped the Anaheim moniker before the 2016 season. So they are now simply the Los Angeles Angels, just as they started. 

The Angels have the third-best winning percentage of all the expansion teams. They’ve been to the playoffs 10 times in 63 years and have a pennant and World Series to show for it. They’ve spent huge money on free agents and were the home to the most talented baseball player in Shohei Ohtani. However, it’s been primarily dysfunctional over the years. 

The dysfunction started at the franchise’s inception and has been the cause for concern lately, but the early to mid-2000 Angels were consistently in the playoffs. In 2002, they won 99 games and defeated the Barry Bonds-led Giants in the World Series. 

From 2004 to 2009, the Angels made the playoffs in five of six years, making the ALCS in two of those years. Vladimir Guerrero was the guy, averaging 29 HR and 103 RBI while hitting .319. 

2010-2012 was about Jared Weaver, finishing in the top five of CY Young voting in three straight seasons. 2012 was when Mike Trout made his mark on Major League Baseball, finishing second in MVP voting in his first full season, and he never looked back. 

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The Angels have always had their guy over various seasons. Jim Fregosi was the man of the 60s. Nolan Ryan was in the 70s. Chuck Finley handled the 80s. Tim Salmon had the 90s. Vlad had the 2000s, and it was all Mike Trout since then. They’ve had some good teams but haven’t surrounded the incredible player with a great team. 

4. Tampa Bay Rays (.486) – 26 Seasons

9 Playoffs, 2 Pennants, 0 World Series

Just missing the medal ceremony is the Tampa Bay Rays, one of the newer expansion teams. In their 26 years of existence, they’ve made the playoffs nine times and have two pennants to show for it. They have yet to win a World Series, but with the model they’ve perfected in Tampa, it’s only a matter of time. 

It took the Rays about 10 years to become relevant since their founding in 1998. The 2007 Tampa Bay Devil Rays were a bottom feeder, winning 66 games. The 2008 name change brought a spark, as they finished the year with 97 wins and rode that momentum to a World Series appearance. 

That 2008 Rays team had six hitters with an OPS+ over 100, and one of the best young rotations in the league, all 26 years old or younger,  led by James Shields and Matt Garza.

That’s been the Rays way ever since. Young, cheap talent who they squeeze the most out of. Since 2008, they’ve made the playoffs nine times, five of which have been in the last five seasons. 

Evan Longoria is their all-time leader in WAR, but guys like Carl Crawford, Ben Zobrist, David Price, and Kevin Kiermaier have all made their marks differently. They have been a contender for some time now, and don’t expect that to stop soon.  

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3. Arizona Diamondbacks (.486) – 26 Seasons

7 Playoff Appearances, 2 Pennants, 1 World Series

Number three is a team I didn’t expect to be ranked this high, but they are hard to ignore. The Arizona Diamondbacks have the fifth-highest winning percentage among expansion teams. They’ve only been around for 26 seasons, but they have seven playoff appearances, two pennants, and a World Series ring against an incredible 2001 Yankees team. 

Arizona wasted no time when they first entered the league. In their second season as a franchise, they made the playoffs after winning 100 regular season games. They won a World Series in their fourth season and then made the playoffs again the following year. 

That 2001 Diamondbacks team was exceptional. Randy Johnson and Curt Schilling gave them one of the best 1-2 punches in the history of Major League Baseball. Luis Gonzalez hit 57 HR that year. Reggie Sanders and Mark Grace had an OPS over .850. 

The Diamondbacks have had rough years but often turn it around quickly.

The most significant gap they’ve had before returning to the playoffs is five seasons. Last season, they made the World Series by sweeping the Dodgers, beating the Phillies in arguably the most challenging place to play in the Majors. 

The Diamondbacks haven’t been around for a long time, but their top five leaders in WAR are pretty damn good. Randy Johnson, Paul Goldschmidt, Brandon Webb, Luis Gonzalez, and Curt Schilling. At one point, all five of those guys were considered one of the best in the league. 

The Diamondbacks also have the best future on this list. They already have an excellent young team coming off a World Series, but they also have a deep-farm system. The sky’s the limit for Arizona, and when the list is re-done in 10 years, they may be at the top. 

2. Toronto Blue Jays (.498) – 47 Seasons

10 Playoff Apperances, 2 Pennants, 2 World Series

The silver medal goes to the Toronto Blue Jays. Among the expansion teams, they have the second-highest winning percentage and the greatest walk-off in baseball history (Joe Carter walk-off video): 10 playoff appearances and two World Series in 47 years. 

From 1985 to 1993, the Blue Jays were one of the best teams in baseball every year. They made the playoffs five times in nine years, with three ALCS appearances and back-to-back World Series titles. While 14 teams can say the same, it hasn’t been done in 23 seasons. 

The all-time Blue Jays WAR leader, Dave Steib, is among the most underrated pitchers ever. He was the Blue Jays’ first star in the early 1980s. From 85-93, the Blue Jays weren’t led by one megastar; it was a bunch of above-average players that all did their job. It was an incredible time to be a Toronto baseball fan. 

After the 1994-1995 strike, the Blue Jays were mediocre until 2014. In 2015 and 2016, they made the ALCS twice. Josh Donaldson won the MVP in 2015 and finished fourth in 2016. Jose Bautista and Edwin Encarnacion were hitting home runs left and right, and the pitching wasn’t electric, but it was fantastic in run prevention. 

Lately, the Blue Jays are in the playoffs almost every year. They’ve made it in three of the last four years, led by Bo Bichette and Kevin Gausman.

They haven’t been past the Wild Card round but are perpetually in the hunt. The Blue Jays project to be competitive for years and have to be in the top three. 

1. Houston Astros (.500) – 62 Seasons

17 Playoff Appearances, 5 Pennants, 2 World Series

The Gold Medal goes to the best team in baseball over the last five years. That would be the Houston Astros. 17 playoff appearances which leads this list. The best winning percentage among all expansion teams. Only the Mets have the same number of pennants with five, and one of six teams on this list has two championships. 

The domination began in 2015. Since that year, they have been to the playoffs eight times, been to the World Series four times, and won two World Series. If they got past the Rangers in 2023, they could won another against the Diamondbacks.

They also project to be one of the best teams in baseball again this year. 

They also had a great run in the late 90s and early 2000s. From 1997 to 2005, they made the playoffs six times and made the World Series in 2005. Morgan Ensberg and Lance Berkman handled the offense, but that pitching staff didn’t need much. One of the best front three’s in a rotation in recent memory, headlined by Roger Clemens, Andy Pettite, and Roy Oswalt. 

The Astros have had plenty of Hall-of-Famers walk through their doors. Jeff Bagwell and Craig Biggio are the first to come to mind, but Nolan Ryan and Joe Morgan also made huge impacts with the Stros. Jose Altuve and Justin Verlander will be enshrined in Cooperstown as soon as they hang them up. Don’t count out Yordan Alvarez, either. 

Baseball fans haven’t been too happy about the Astros post-cheating scandal, but you can’t doubt their greatness since then. Since 2017, they haven’t missed the playoffs and even won another ring. While it took them a while to get going, like most expansion teams, they now reign supreme. 

Hopefully we can re-do this list in the next 10 years to add a few more teams to this list.