<P> The Major League Baseball single - season record for the number of home runs hit by a batter has changed many times over the years . </P> <Table> <Tr> <Th> Batter </Th> <Th> Team </Th> <Th> Age </Th> <Th> Year </Th> <Th> HR </Th> <Th> Reign </Th> <Th> Record breaker </Th> </Tr> <Tr> <Td> George Hall </Td> <Td> Philadelphia Athletics </Td> <Td> 27 </Td> <Td> 1876 </Td> <Td> 5 </Td> <Td> 3 years </Td> <Td>--</Td> </Tr> <Tr> <Td> Charley Jones </Td> <Td> Boston Red Caps </Td> <Td> 29 </Td> <Td> 1879 </Td> <Td> 9 </Td> <Td> 4 years </Td> <Td> 6th on July 31 off George Bradley </Td> </Tr> <Tr> <Td> Harry Stovey </Td> <Td> Philadelphia Athletics </Td> <Td> 27 </Td> <Td> 1883 </Td> <Td> 14 </Td> <Td> 1 year </Td> <Td> 10th on August 1 off Jack Neagle </Td> </Tr> <Tr> <Td> Ned Williamson </Td> <Td> Chicago White Stockings </Td> <Td> 27 </Td> <Td> 1884 </Td> <Td> 27 </Td> <Td> 35 years </Td> <Td> 15th on July 9 off Ed Bagley </Td> </Tr> <Tr> <Td> Babe Ruth </Td> <Td> Boston Red Sox </Td> <Td> 24 </Td> <Td> 1919 </Td> <Td> 29 </Td> <Td> 1 year </Td> <Td> 28th on September 24 off Bob Shawkey </Td> </Tr> <Tr> <Td> Babe Ruth </Td> <Td> New York Yankees </Td> <Td> 25 </Td> <Td> 1920 </Td> <Td> 54 </Td> <Td> 1 year </Td> <Td> 30th on July 19 off Dickie Kerr </Td> </Tr> <Tr> <Td> Babe Ruth </Td> <Td> New York Yankees </Td> <Td> 26 </Td> <Td> 1921 </Td> <Td> 59 </Td> <Td> 6 years </Td> <Td> 55th on September 15 off Bill Bayne </Td> </Tr> <Tr> <Td> Babe Ruth </Td> <Td> New York Yankees </Td> <Td> 32 </Td> <Td> 1927 </Td> <Td> 60 </Td> <Td> 34 years </Td> <Td> 60th on September 30 off Tom Zachary </Td> </Tr> <Tr> <Td> Roger Maris </Td> <Td> New York Yankees </Td> <Td> 27 </Td> <Td> 1961 </Td> <Td> 61 </Td> <Td> 37 years </Td> <Td> 61st on October 1 off Tracy Stallard </Td> </Tr> <Tr> <Td> Mark McGwire </Td> <Td> St. Louis Cardinals </Td> <Td> 35 </Td> <Td> 1998 </Td> <Td> 70 </Td> <Td> 3 years </Td> <Td> 62nd on September 8 off Steve Trachsel </Td> </Tr> <Tr> <Td> Barry Bonds </Td> <Td> San Francisco Giants </Td> <Td> 36 </Td> <Td> </Td> <Td> 73 </Td> <Td> 17 years </Td> <Td> 71st on October 5 off Chan Ho Park </Td> </Tr> </Table> <Tr> <Th> Batter </Th> <Th> Team </Th> <Th> Age </Th> <Th> Year </Th> <Th> HR </Th> <Th> Reign </Th> <Th> Record breaker </Th> </Tr>

What is the mlb home run record in a season