Complex sentence: Hartsfield managed the Jays from 1977 to 1979, compiling a record of 166--318 (.343) in 484 games, and finishing last in the American League East Division each season.
Split into simpler sentences: Hartsfield managed the Jays from 1977 to 1979, compiling a record of 166--318 (.343) in 484 games. The fledgling Jays finished last in the American League East Division each season.