The Best Boston Red Sox Seasons and Every October Run

By 4Baseball Staff · November 5, 2026 · 12 min read

A guide to the best regular seasons in Boston Red Sox history and all 41 postseason series the club has played, from 1903 to 2025, with the titles, the seven-game heartbreaks and the near-misses.

The Boston franchise has won 14 American League pennants and nine World Series, and the strange part is how the titles are bunched. Five came between 1903 and 1918, then nothing for 86 years, then four more between 2004 and 2018. In between sit four pennants that each ended in a seventh game lost, plus a long list of good teams that never reached October at all. This article walks through the regular seasons that mattered and every postseason series the club has played, in order, using the historical record for the results.

Two cautions before the tour. First, the best team by record is not always the one that won the title. The 1946 club won 104 games and lost the Series; the 2004 club won 98 and is remembered as the team that ended an 86-year wait. Second, the postseason itself changed shape over the years: no playoff rounds at all before 1969, two divisions and a league championship series from then on, a wild card from 1995, and a one-game or three-game wild-card round in the modern years. A "series" in 1912 and a "series" in 2021 are not the same size of test.

The record behind the October runs

Over 125 seasons, 1901 through 2025, the club's regular-season record is 10,044 wins and 9,336 losses, a winning percentage of .518. That is a good but not dominant long-run mark, and it hides two very different franchises: a dynasty in the 1910s, a basement dweller in the 1920s and early 1930s, and a contender most years after 1967.

The postseason ledger is clearer. The club has played 41 postseason series through 2025 and won 24 of them. Nine of the 13 World Series it reached were victories. The 14th pennant, in 1904, produced no Series at all, because the National League champion declined to play, so the historical record lists no World Series for that year.

Note the overlap. The club won the 2004 World Series as a wild card, and it reached the 2025 postseason the same way. A division title is a regular-season honour; a pennant is awarded for winning the league's postseason bracket, and the table shows how often those two lists differ.

The Americans and the first dynasty, 1903 to 1918

The franchise began as the Boston Americans and took the name Red Sox in 1908. Its first great team went 91-47 in 1903 and met the Pittsburgh Pirates in the first modern World Series, a best-of-nine, winning five games to three. Cy Young pitched for the club from 1901 to 1908 and still shares the club record for career victories, 192, with Roger Clemens; his 2.00 career ERA for the franchise is second in club history among pitchers with 1,000 innings.

The Americans won the pennant again in 1904 with a 95-59 record, but there was no Series. They did not win another until 1912, and that year's team is still the best regular-season club the franchise has produced by winning percentage: 105-47, a pace of about 112 wins over 162 games. It beat the New York Giants four games to three, and one game in the Series ended in a tie when it was called for darkness, so the Series took eight games. Tris Speaker won the league's Most Valuable Player award that season. It was also the year the club moved into Fenway Park, which opened in 1912.

The next three titles came in a flurry:

• 1915: 101-50, beating the Philadelphia Phillies four games to one.
• 1916: 91-63, beating Brooklyn four games to one.
• 1918: 75-51 in a season cut short by World War I, beating the Chicago Cubs four games to two.

Babe Ruth's presence runs through the second half of that stretch, and it is worth separating the two Ruths. As a pitcher for Boston he posted a 2.19 ERA over his club career, the fourth-lowest among Boston pitchers with 1,000 innings, behind Smoky Joe Wood (1.99), Cy Young (2.00) and Dutch Leonard (2.13). In 1916 he went 23-12 with a 1.75 ERA and 23 complete games. Then he was sold to the Yankees after the 1919 season, and the later "Curse of the Bambino" story grew from the 86 years that followed. Whatever you think of the curse, the timing is real: the club that had won five titles in 16 years did not win a sixth until 2004.

From last place to the edge of a title, 1925 to 1949

The 1920s were as bad as the 1910s were good. The historical list of the club's five worst seasons by winning percentage in the modern era includes four from this stretch: 47-105 in 1925, 46-107 in 1926, 51-103 in 1927 and 43-111 in 1932, the worst season in franchise history. (The fifth, 49-105, belongs to the 1906 Americans.) The club finished last, eighth of eight, in each of those four years.

Tom Yawkey bought the team in 1933 and put money into the roster and into Fenway, which was rebuilt in the mid-1930s; historical marks the start of the "second" Fenway in 1934. Joe Cronin, the shortstop, became player-manager in 1935 and managed through 1947 with a 1,071-916 record, the most games of any manager in club history. Ted Williams arrived in 1939.

The result was a run of strong teams that kept finishing a step behind, and then the one year they did not.

1. 1946: 104-50, the best record in the American League, and the club's first pennant since 1918. It lost the World Series to the St. Louis Cardinals, three games to four. Williams won the MVP award that year.
2. 1948: 96-59 by the historical count, which includes a one-game playoff loss to Cleveland after the two clubs finished the regular season tied for first.
3. 1949: 96-58, one game behind the Yankees, who won the pennant. Williams won his second MVP award.

Boston won 94 or more games in four seasons between 1946 and 1950 (104, 96, 96 and 94), and it won one pennant. The tail end of that run, 1950 (94-60) and 1951 (87-67), finished third. The era is a good argument against judging a team by its trophies alone; the 1949 club's 896 runs scored against 667 allowed describe a very good team that needed the Yankees to lose one more game and did not get it.

The seven-game habit: 1967, 1975 and 1986

After the 1950s, the club slid. It finished 65-89 in 1960, seventh in an eight-team league, and 72-90 in 1966, ninth in a ten-team league. Then came 1967, the "Impossible Dream" season: 92-70, first in the American League by a single game over the field, and a pennant for the first time since 1946. Carl Yastrzemski won the Triple Crown that year, batting .326 with 44 home runs and 121 RBI, and was named MVP. Jim Lonborg won the Cy Young Award. The Series went the distance and Boston lost it to St. Louis, three games to four.

That sets up one of the odder patterns in baseball. Boston's four pennants between 1946 and 1986 all produced a seven-game Series, and Boston lost all four:

The 1975 club won its division and then swept Oakland in the American League Championship Series, three games to none, and Fred Lynn won both Rookie of the Year and MVP that season. The Series against the Reds is regarded as one of the best ever played, and it ended 4-3 for Cincinnati.

The 1986 team won 95 games and a division title, then beat the California Angels in the ALCS four games to three, after trailing that series three games to one. In the World Series against the Mets, Boston led three games to two and lost the last two. Roger Clemens won both the MVP award and the Cy Young Award that year. Between those two teams sits 1978, when the club finished 99-64 on the historical count. That figure includes a one-game playoff against the Yankees, lost after the two teams tied for the division lead, and the game has its own place in baseball memory. It is not in the ledger below because a one-game tiebreaker is not a series.

Division titles, sweeps and the wild-card years, 1988 to 2002

Two division titles in three years, 1988 and 1990, ended in the same way: a four-game sweep by the Oakland Athletics in the ALCS. The 1995 club won the division at 86-58 in the strike-shortened season (Mo Vaughn was the MVP) and was swept by Cleveland in the first round, 0-3.

The wild card changed the math. In 1998 the club won 92 games and reached the postseason as a wild card, but lost the division series to Cleveland, one game to three. In 1999 it met Cleveland again and won the series three games to two, after losing the first two games. It then met the Yankees in the ALCS and lost four games to one. Pedro Martinez had one of the best seasons by any Boston pitcher that year: 23-4 with a 2.07 ERA and 313 strikeouts, and he followed it in 2000 with an 18-6 mark and a 1.74 ERA. The club did not reach the postseason in 2000, a reminder that even a pitching season that good does not by itself make October.

The pattern for the era is plain from the ledger. From 1988 through 1999 Boston reached the postseason five times, won a single series (1999's division round), and lost every ALCS it reached, to Oakland twice and then to New York. The players were excellent; the October results were not.

2003 and 2004: the same opponent, two different endings

In 2003 Boston won 95 games, finished second to the Yankees, and took the wild card. It beat Oakland in the division series after trailing two games to none, then played the Yankees in the ALCS and lost in seven games, three to four, in a series that ended on a home run in the 11th inning of Game 7 (Aaron Boone's, well documented). It joined the four lost World Series as one more seventh-game defeat.

The following year the roster was largely the same and the outcome was not. The 2004 club went 98-64, again finishing second to the Yankees and again taking the wild card. It swept the Angels in the division series and met the Yankees in the ALCS. Boston lost the first three games, then won four straight and took the series four games to three, the only time in major-league history that a team has won a best-of-seven after losing its first three. The World Series against St. Louis was anticlimactic by comparison: a four-game sweep, the club's first title since 1918. Manny Ramirez hit 43 home runs that season and David Ortiz hit 41 with 139 RBI; the pitching was less dominant than the hitting, but good enough.

Terry Francona managed the club from 2004 to 2011 with a 744-552 record, the second-most wins of any manager in franchise history and the manager of both of the first two titles of the century.

Three more titles: 2007, 2013 and 2018

The 2007 team, 96-66, was the first of the new century to win a division. It beat the Angels in the division series (a sweep), came from three games to one down against Cleveland in the ALCS to win four games to three, and then swept Colorado in the World Series, four games to none. It was the second World Series sweep in four years for a club that had never swept one before.

In 2008 the club won 95 games, took the wild card, beat the Angels in the division series (three games to one), and lost the ALCS to Tampa Bay in seven games. The Rays, whose own story is in the franchise-history article linked below, won that seventh game. A first-round sweep by the Angels in 2009 followed, and then three seasons without a postseason berth.

The 2013 team won 97 games, took the division, beat Tampa Bay three games to one, beat Detroit four games to two, and won the World Series against St. Louis. The historical table lists that Series as four games to three, which does not match the official record of four games to two; check MLB.com if you need the game-by-game line. Ortiz hit 30 home runs with 103 RBI and a .309 average that year.

Then 2018. The Red Sox won 108 games and lost 54, the highest win total in franchise history and the fourth-best winning percentage (.667) on the club's list behind the 1912, 1946 and 1915 teams. Mookie Betts won the MVP award, batting .346 with 32 home runs and 129 runs scored. The club beat the Yankees three games to one in the division series, Houston four games to one in the ALCS, and the Dodgers four games to one in the World Series, losing only three postseason games in all. By any measure it is the best Boston team of the modern era.

The recent years, 2016 to 2025

After the titles, the October results thinned. The division winners of 2016 and 2017 lost the division series both times (0-3 to Cleveland and 1-3 to Houston). The 2021 club won 92 games and took a wild card, which it used well: it won the wild-card game against the Yankees (the only game), beat Tampa Bay in the division series three games to one, and lost the ALCS to Houston four games to two.

In 2025 the club went 89-73, finished third in the AL East, and entered the wild-card round, where it lost to the Yankees, one game to two. That is the last series in the historical record. Alex Cora, who managed the 2018 title team, had managed 1,133 games for the club through 2025, with a 609-524 record.

Every series, in one table

The full ledger, with Boston's game record listed first:

Read down the right-hand column and a few facts fall out. Boston has been swept in a postseason series six times (1988, 1990, 1995, 2005, 2009 and 2016) and has swept an opponent five times (the 1975 ALCS, and the division series and World Series in both 2004 and 2007). The club has never lost a World Series in fewer than seven games.

Common questions

Which Red Sox team had the best regular season? By winning percentage among seasons of 100 or more games, the 1912 team's 105-47 (.691) leads, followed by the 1946 club at 104-50 and the 1915 club at 101-50. By total wins, the 2018 club's 108 is the highest in franchise history. The 1912 schedule was 154 games and the 2018 schedule was 162, so the percentages compare more fairly than the win totals do.

Did Boston ever win a pennant without winning a World Series in the same year? Yes, five times: 1904 (no Series was played), 1946, 1967, 1975 and 1986. Each of the last four lost a seventh game.

What was the worst Red Sox season? The 1932 club, 43-111, finished eighth in the eight-team American League. Four of the five worst seasons in club history came between 1925 and 1932.

Has Boston ever won the World Series as a wild card? Once, in 2004. The 2007, 2013 and 2018 champions all won the division, and the five titles from 1903 to 1918 came before divisions existed.

Does historical count playoff games in a team's record? Where a one-game playoff broke a tie for the division or pennant, as in 1948 and 1978, it is included in the win-loss totals, which is why those clubs show 96-59 and 99-64. The postseason series themselves are listed separately.

Where to go next

For the full story of the franchise, from its 1901 start to the present, read the history of the Boston Red Sox and the best players in club history; the park these teams played in is covered in the Fenway Park guide. The rivals who recur in this ledger are in the Yankees' history, the Orioles' history and the Rays' history, and the way the Series itself has been organised is explained in the history of the World Series. To follow the club now, see the Red Sox team page, the Fenway Park page and the Red Sox topic page.