The Ephs and Polar Bears first met in 1926, but there have been several large gaps in the schedule since then.
Williams holds a 32-1 lead in the series thorugh 2010-11.
| Year | Winner | Location (W/B) |
Score | Tournament |
| 2011 | Williams | W | 5-4 | |
| 2010 | Williams | B | 7-2 | |
| 2009 | Williams | W | 5-1 | NCAA |
| 2009 | Williams | W | 6-3 | |
| 2008 | Williams | B | 8-1 | |
| 2007 | Williams | N |
5-1 | NCAA |
| 2007 | Williams | N | 5-0 | NESCAC |
| 2007 | Bowdoin | W | 5-4 | |
| 2005 | Williams | B | 4-1 | NCAA |
| 2004 | Williams | W |
7-0 | NCAA |
| 2003 | Williams | B |
4-3 | NCAA |
| 2001 | Williams | W |
7-0 | NCAA |
| 2000 | Williams | W |
6-1 | NCAA |
| 1997 |
Williams |
W |
4-0 |
NCAA |
| 1955 |
Williams |
W |
9-0 |
|
| 1953 |
Williams |
W |
9-0 |
|
| 1952 |
Williams |
W |
7-2 |
|
| 1951 |
Williams |
W |
8-1 |
|
| 1950 |
Williams |
W |
8-1 |
|
| 1949 |
Williams |
W |
7-2 |
|
| 1941 |
Williams |
W |
8-1 |
|
| 1940 |
Williams |
W |
9-0 |
|
| 1938 |
Williams |
W |
7.5-1.5 |
|
| 1937 |
Williams |
W |
9-0 |
|
| 1936 |
Wiliams |
W |
9-0 |
|
| 1930 |
Williams |
W |
8-1 |
|
| 1929 |
Williams |
W |
6-1 |
|
| 1926 |
Williams |
W |
6-0 |
