What year did an NFL team not lose a game all year?
1972 Miami dolphins
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1972
1966
1972
1966
1972
1966
1972
1966
1972
1966
1966
1932
1966
1927
1932
1922
1966
1927
1964
1932
1922
1966
1931
1964
1927
1939
1966
1932
1922
1921
1964
1931
1966
1926
1927
1939
1932
1922
1921
1964
1924
1966
1931
1926
1927
1939
1964
1932
1922
1921
1966
1924
1931
1964
1926
1927
1939
2002
1966
1932
1922
1921
1924
1923
1964
1931
2002
1966
1926
1927
1939
1932
1922
1921
1964
1924
1923
2002
1966
1931
1926
1927
1939
1964
1984
1932
1922
1921
2002
1966
1924
1923
1931
1964
1984
1926
1927
1939
2002
1966
1932
1922
1921
1924
1923
1964
1984
1931
2002
1966
1926
1927
1939
1932
1922
1921
1964
1984
1924
2002
1966
1931
1926
1923
1982
1927
1939
1964
1984
1932
1922
1921
2002
1924
1982
1931
1964
1984
1926
2007
1927
1939
2002
1975
1932
1922
1998
1921
1924
1923
1982
1964
1984
2007
1925
1931
2002
1975
1926
1969
1927
1939
1985
1998
1932
1982
1922
1921
1964
1984
1924
2007
1974
1925
2002
1973
1975
1969
1996
1991
1985
1998
1931
1926
1923