What is the greatest team ever? How did the best teams do against other good teams and in different series (set of games against a team at a time)? WP = Winning Percentage.

1927 NEW YORK YANKEES

Regular Season W-L

110-44 (.714 WP)

Pythagorean W-L

109-45 (.708 WP)

W-L VS Teams Over .500

42-24 (season only/.636 WP), 46-24 (with playoffs/.657 WP)

1939 NEW YORK YANKEES

Regular Season W-L-D

106-45-1 (.697 WP)

Pythagorean W-L

111-40 (.735 WP)

W-L VS Teams Over .500

53-32 (season only/.624 WP), 57-32 (with playoffs/.640 WP)

1998 NEW YORK YANKEES

Regular Season W-L

114-48 (.704 WP)

Pythagorean W-L

108-54 (.667 WP)

W-L VS Teams Over .500

33-21 (season only/.611 WP), 44-23 (with playoffs/.657 WP)

2018 BOSTON RED SOX

Regular Season W-L

108-54 (.667 WP)

Pythagorean W-L

103-59 (.636 WP)

W-L VS Teams Over .500*

56-37 (regular season only/.602 WP), 67-40 (with playoffs/.626 WP)

*I excluded the Pittsburgh Pirates due to them being barely above .500 and their Pythagorean record being below.

1905 NEW YORK GIANTS

Regular Season W-L-D

105-48-2 (.677 WP)

Pythagorean W-L

105-48 (.686 WP)

W-L-D VS Teams Over .500

54-33-2 (regular season only/.607 WP), 58-34-2 (with playoffs/.617 WP)

1906 CHICAGO CUBS

Regular Season W-L-D

116-36-3 (.748 WP)

Pythagorean W-L

115-37 (.742 WP)

W-L-D VS Teams Over .500

30-12-1 (regular season only/.698 WP), 32-16-1 (including playoffs/.653 WP)

1942 ST. LOUIS CARDINALS

Regular Season W-L-D

106-48-2 (.679 WP)

Pythagorean W-L

107-47 (.695 WP)

W-L-D VS Teams Over .500

28-16 (regular season only/.636 WP), 32-17 (with playoffs/.653 WP)

1975 CINCINNATI REDS

Regular Season W-L

108-54 (.667 WP)

Pythagorean W-L

107-55 (.660 WP)

W-L VS Teams Over .500*

29-25 (regular season only/.537 WP), 36-28 (with playoffs/.563 WP)

*. I omitted the St. Louis Cardinals because they were barely above .500 and should not have been at all based on their Pythagorean record.

2001 SEATTLE MARINERS

Regular Season W-L

116-46. (.716 WP)

Pythagorean W-L

109-53. (.673 WP)

W-L VS Teams Over .500

45-23 (regular season only/.662 WP), 49-29 (with playoffs/.628 WP)

*I excluded the Chicago White Sox and the New York Mets who were barely above and should’ve been below based on their Pythagorean record.