In 2004, Bonds had perhaps his best season. He hit .362 en route to his second National League batting title, and broke his own record by walking 232 times. He slugged .812, which was fourth-highest of all time, and broke his on-base percentage record with a .609 average. Bonds passed Mays on the career home run list by hitting his 661st off of Ben Ford (baseball) on April 13, He then hit his 700th off of Jake Peavy on September 17. Bonds hit 45 home runs in 373 at-bats, and struck out just 41 times, putting himself in elite company, as few major leaguers have ever had more home runs than strikeouts in a season. Bonds would win his fourth consecutive MVP award and his seventh overall. His seven MVP awards are four more than any other player in history. In addition, no other player from either league has been awarded the MVP four times in a row. (The MVP award was first given in 1931). The 40-year-old Bonds also broke Willie Stargells 25-year record as the oldest player to win a Most Valuable Player Award (Stargell, at 39 years, 8 months, was National League co-MVP with Keith Hernandez in 1979). On July 4, he tied and passed Rickey Hendersons career bases on balls record with his 2190th and 2191st career walks.
Question: How many career home runs was Mays record?
Answer: 660