The Best Single-Season Teams by Winning Percentage

By 4Baseball Staff · November 5, 2026 · 10 min read

The best regular seasons in major league history ranked by winning percentage, from the 1906 Cubs at .763 to the 2001 Mariners and 1998 Yankees, with context on schedules, opponents and what happened in October.

The 1906 Chicago Cubs won 116 games and lost 36, a winning percentage of .763 that no major league team since has approached. The 2001 Seattle Mariners also won 116 games, but they lost 46, because the schedule had grown from 154 games to 162, and their percentage was .716. The two clubs share the record for wins in a season, and they sit at opposite ends of a century of changes in how baseball is organized. They also share a footnote: neither won the World Series.

That footnote is the real subject of this article. A winning percentage is the cleanest summary of a regular season, and ranking the top teams is easy. Understanding what the ranking means is harder. This piece lists the best teams of the modern two-league era from the historical record, explains how to compare a 154-game season with a 162-game one, looks at five of the most famous teams (the 1906 Cubs, the 2001 Mariners, the 1998 Yankees, the 1954 Indians and the 1927 Yankees), and shows with a worked example why even a team that wins seven games of every ten can lose a short series.

How the ranking works, and the rules used here

Winning percentage is wins divided by the sum of wins and losses. A team that goes 116-36 divides 116 by 152 and gets .763. It is the standard measure because it works across schedules of different lengths: a team that wins 100 of 154 games is at .649, and one that wins 105 of 162 is at .648, which is nearly the same level of dominance even though the second has five more wins.

Three rules shaped the list. I used only the American and National Leagues, because the historical record also carries Negro leagues from 1920 to 1948, but those teams played schedules of varying lengths against uneven competition, and a fair comparison would need its own article. I limited the main list to seasons since 1901, when the two major leagues began playing side by side, and to teams that played at least 100 games, which removes very short seasons. And I report the 19th-century record separately, since the leagues of the 1880s played about 110 to 130 games under rules and rosters unlike anything since.

The top 14 teams since 1901

Two entries, the Pirates of 1902 and the Giants of 1904, played in years when there was no World Series between the leagues, so their results cannot be measured against a champion. The rest of the list divides 7 to 5 in favor of winners: seven teams won the Series, four lost it, and the 2001 Mariners did not reach it.

The 1906 Cubs: a record that survives its context

The Cubs of 1906 scored 704 runs and allowed 381, a gap of 323 runs over the season, in a major-league environment that averaged 3.62 runs per team game. Mordecai Brown posted a 1.04 earned run average, which led the league, and Jack Pfiester (1.51) and Ed Reulbach (1.65) ranked second and third. The club's pitching staff produced the three lowest earned run averages of any National Leaguer who pitched enough innings to qualify. In their 152 decisions, they won more than three games out of four.

The context matters in both directions. The league had eight teams, and the Cubs played the weakest of them frequently: the Boston Beaneaters went 49-102 and the St. Louis Cardinals 52-98. A team that feasts on two or three terrible opponents sees its winning percentage rise without any change in its quality. At the same time, the Cubs were not merely good against the bad. The New York Giants won 96 games and the Pittsburgh Pirates 93 that year, and Chicago finished 20 games ahead of the Giants.

Then came the Series. The Cubs met the Chicago White Sox, the American League champions at 93-58, and lost four games to two. The White Sox hit so poorly across the season that history gave them the nickname Hitless Wonders, which makes the upset one of the best-known in baseball.

Pittsburgh's two great teams: 1902 and 1909

The Pirates appear twice. In 1902 they went 103-36, a .741 percentage in a schedule of about 140 games, scoring 775 runs and allowing 440. There was no World Series that year, since the leagues had not yet agreed to meet in October, so the club's dominance ended with the pennant. In 1909 they went 110-42, and this time there was a Series, which they won over the Detroit Tigers four games to three. That team included Honus Wagner, who hit .339 and led the National League in runs batted in. For the player's own story, read the profile of Honus Wagner.

1927 and the Yankee dynasty teams

Four Yankee teams sit in the top 14: 1927, 1939, 1932 and 1998. The 1927 club went 110-44 and scored 975 runs while allowing 599, then swept the Pirates in the World Series. Babe Ruth hit 60 home runs that year and Lou Gehrig hit 47 and won the American League Most Valuable Player award. The home run rate in the 1927 major leagues was just 0.37 per team game, so a lineup with two men hitting that many was without peer. For Gehrig's career, see Lou Gehrig.

The 1939 club went 106-45 and swept the Cincinnati Reds, with Joe DiMaggio as the American League's Most Valuable Player. It is the most interesting case for the next section, because its runs scored (967) and allowed (556) suggested a still better record than the one it posted.

The 1998 Yankees: 125 wins in all

The 1998 Yankees won 114 games and lost 48, a .704 percentage that is the best of any club in the modern 162-game era except the Mariners of 2001. They scored 965 runs and allowed 656. They then swept the Texas Rangers in the division series, beat the Cleveland Indians four games to two for the pennant, and swept the San Diego Padres in the World Series. That series record is 11 wins and 2 losses, which, added to the regular season, gives 125 wins and 50 losses for the full year.

Two features of that team are worth noting. First, they outscored their opponents by 309 runs, yet neither the league's leading home run hitter (Ken Griffey of the Mariners, with 56) nor its Most Valuable Player (Juan Gonzalez of the Rangers) wore a Yankee uniform. Second, they won the division by a wide margin over a decent field: the second-place Boston Red Sox were 92-70.

The 1954 Indians: 111 wins and a sweep

Cleveland's 1954 club went 111-43, which was .721 and stood as the American League record for wins until the 1998 Yankees won 114. It scored 746 runs and allowed 504. It finished eight games ahead of the Yankees, who won 103 games, and the pennant was the club's first since 1948. The team then ran into the New York Giants in the World Series and lost four straight.

That loss is one of the best-known upsets in World Series history, and it came in a season in which the National League champion won 97 games, not 111. The series included Willie Mays's famous catch in the opening game at the Polo Grounds, which is covered in the story of that ballpark. Part of the explanation for the Indians' regular-season total is the bottom of the league: the Baltimore Orioles won 54 games and the Philadelphia Athletics 51, which gave Cleveland and the Yankees plenty of games they were expected to win. A short series against a strong opponent offers none of that.

The 2001 Mariners: the most wins since 1906

Seattle won 116 games and lost 46, tying the Cubs' record for wins. They scored 927 runs and allowed 627, a gap of 300, and they did it in the American League West, where the Oakland Athletics won 102 games and still finished second. Ichiro Suzuki won both the American League Most Valuable Player award and the Rookie of the Year award, leading the league with a .350 average and 242 hits and 56 stolen bases. Freddy Garcia's 3.05 earned run average led the league.

The postseason was a disappointment. Seattle beat Cleveland in five games in the division series, then lost to the Yankees four games to one in the American League Championship Series, and New York went on to lose the World Series to Arizona in seven games. In a sense, 2001 is the weak point in the narrative that great regular seasons predict championships. The team that won 116 games did not play in the final, and the team that won it had won 92.

The league also looked different. In 2001 there were 30 teams, with weak clubs such as Tampa Bay (62-100) and Detroit (66-96) in the same league. More teams mean more weak teams to beat, and that is one reason a 116-win total in 2001 is not simply more impressive than a 111-win total in 1954.

What runs scored and allowed predict

A well-known estimate, Bill James's Pythagorean formula, predicts a team's winning percentage from its runs scored (R) and runs allowed (RA): R squared divided by the sum of R squared and RA squared. It is a way to ask whether a team's record was lucky.

The 1939 Yankees won fewer games than their run totals implied, by about seven or eight over a schedule of about 152 games. The 1954 Indians and 2001 Mariners did the opposite, winning about five games more than the formula predicts. Part of that difference is luck, since a team that wins a lot of close games tends not to repeat the pattern, and part is real, for example a bullpen that saves one-run leads. The lesson is that the record in the table is a measurement of what happened, not a perfect measure of how good the team was.

Why a .716 team can lose a short series

Suppose a team that wins 71.6 percent of its games meets a team that wins 56 percent. A rough estimate, from Bill James's log5 method, gives the better team about a 66 percent chance in any one game. Over a best-of-seven series, that works out to about 82 percent, and over a best-of-five, about 79 percent. So the dominant team loses roughly one series in five against a good but not great opponent. The 1954 Indians, 1906 Cubs and 2001 Mariners were not shocking exceptions. They were the kind of loss that the arithmetic says will happen to some of the great teams.

This also explains why regular-season greatness and championships are separate achievements. Over 162 games, luck washes out; over four to seven games it does not. The shape of the current playoff system, covered in how the MLB postseason works, adds extra rounds that make the problem larger, because a team has to win more than one short series to win the title.

Before 1901: the earlier leaders

The historical record shows better winning percentages than 1906, but they come from a different game. The 1885 Chicago White Stockings went 87-25, a .777 percentage in 112 games, and the 1885 New York Giants went 85-27, or .759. The Providence Grays of 1884 went 84-28, which is .750. These totals came in leagues of eight teams that played far fewer games, with different pitching rules. Many historians treat the modern era as beginning in 1901 for exactly that reason, and that is why this article does not rank them with the Cubs. They are a reminder that the 1906 record is the best of the two-league era, not the best of all time in an absolute sense.

Common questions

Is the 2001 Mariners' 116-46 the best record ever? It ties the most wins ever, with the 1906 Cubs, but the Cubs' winning percentage was higher because they played 152 decisions rather than 162. By winning percentage, the Mariners rank fifth since 1901.

How many games did the 1998 Yankees win in all? Their 11-2 record in the division series, the pennant series and the World Series, added to the 114 regular-season wins, gives 125 wins against 50 losses for the full year.

Do the Negro leagues have teams that would rank? Possibly. The historical record includes league standings for 1920 to 1948, but schedules differed widely from club to club, and the records are incomplete, so I left them out of the ranking instead of guessing.

Why are there so many Yankees? The club won the American League pennant in many of the years from 1921 on. The list above includes four Yankee teams in 14 places, and each came from a different generation of players.

Where to go next

For the opposite end of the table, read the worst seasons in baseball history. For the hitters who made the best teams hard to beat, see every Triple Crown winner, the last batters to hit .400 and the stolen base leaders and the running game. Teams of the 1998 and 2001 kind drew talent from several countries, and baseball in the Dominican Republic describes one of the largest sources. Current records are on the standings page, and the history topic page collects more.