11 teams are tied for losing the most games when the run differential has been 2 or above runs in a month, with 1 loss. The first three are the Miami Marlins in September 2016, the Washington Senators in September 1971 and the New York Giants in September 1942.
| TEAM | L | DIFF | MONTH | W | L% | G | W% | AB | R | H | 2B | 3B | HR | RBI | BB | HBP | SO | SB | CS | PA | TB | XBH | SH | SF | IBB | GIDP | AVG | OBP | SLG | OPS | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 |  | Marlins | 1 | 29 | September 2016 | 9 | .100 | 10 | .900 | 359 | 56 | 107 | 18 | 5 | 7 | 52 | 30 | 5 | 61 | 17 | 1 | 404 | 156 | 30 | 4 | 6 | 6 | 11 | .298 | .355 | .435 | .790 |
| 2 |  | Senators | 1 | 23 | September 1971 | 6 | .143 | 7 | .857 | 266 | 41 | 77 | 12 | 2 | 5 | 36 | 34 | 0 | 40 | 9 | 5 | 309 | 108 | 19 | 6 | 3 | 4 | 9 | .289 | .366 | .406 | .772 |
| 3 |  | Giants | 1 | 52 | September 1942 | 11 | .083 | 12 | .917 | 388 | 73 | 115 | 18 | 3 | 8 | 69 | 55 | 1 | 32 | 3 | 452 | 163 | 29 | 8 | 12 | .296 | .385 | .420 | .805 | |||
| 4 |  | Senators | 1 | 63 | August 1941 | 14 | .067 | 15 | .933 | 570 | 102 | 192 | 40 | 15 | 8 | 96 | 40 | 2 | 38 | 9 | 619 | 286 | 63 | 7 | 16 | .337 | .382 | .502 | .884 | |||
| 5 |  | Cubs | 1 | 25 | October 1907 | 3 | .250 | 4 | .750 | 129 | 34 | 48 | 10 | 3 | 0 | 16 | 0 | 18 | 149 | 64 | 13 | 4 | .372 | .441 | .496 | .938 | ||||||
| 6 |  | Pirates | 1 | 28 | June 1897 | 7 | .125 | 8 | .875 | 56 | ||||||||||||||||||||||
| 7 |  | Colts | 1 | 12 | April 1892 | 3 | .250 | 4 | .750 | 30 | ||||||||||||||||||||||
| 8 |  | Orioles | 1 | 25 | October 1891 | 3 | .250 | 4 | .750 | 42 | ||||||||||||||||||||||
| 9 | Gladiators | 1 | 21 | July 1890 | 4 | .200 | 5 | .800 | 45 | |||||||||||||||||||||||
| 10 | Spiders | 1 | 19 | July 1887 | 3 | .250 | 4 | .750 | 28 | |||||||||||||||||||||||
| 11 | Cowboys | 1 | 10 | August 1884 | 2 | .333 | 3 | .667 | 17 | |||||||||||||||||||||||
| 12 | Grays | 1 | 64 | July 1883 | 11 | .083 | 12 | .917 | 106 |
Some of the information used here was obtained free of charge from Retrosheet.
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