The 2001 record season

Bonds hit his 73rd home run on October 7, 2001 against the Dodgers’ Dennis Springer at Pacific Bell Park, San Francisco. The 2001 Giants went 90-72 but missed the playoffs by two games. Bonds also walked 177 times that year (still a single-season record), set the MLB record for slugging percentage at .863 (broke Babe Ruth’s 1920 mark), and was the unanimous NL MVP — his fourth of an eventual seven.

The home-run pace was historically front-loaded. Bonds hit 39 by the All-Star break (a record at the time), 50 by August 11 (also a record pace), and 70 on October 4 — three games before Springer’s pitch in game 162. Springer was throwing a knuckleball; Bonds caught one belt-high and hit it to right-center, lower deck.

The 1998 race that re-set the bar

Three years earlier, Mark McGwire (Cardinals) and Sammy Sosa (Cubs) waged the most-watched home-run race in MLB history, both eventually passing Roger Maris’s 1961 record of 61. McGwire finished with 70, Sosa with 66. Maris’s number had stood for 37 years; the 1998 race ended it in eight weeks of head-to-head pursuit between September and the end of the regular season.

All four members of the 70+ club (Bonds 73, McGwire 70/65, Sosa 66/64/63) played in the late-1990s/early-2000s offensive era and all became central figures in the steroid investigations of the 2000s. None were elected to the Baseball Hall of Fame in their primary windows of eligibility. Bonds dropped off the writers’ ballot after 2022; McGwire after 2016; Sosa after 2022.

The post-testing leaderboard

Major League Baseball implemented mandatory PED testing in 2003. The post-testing single-season leaders read very differently: Aaron Judge (62 in 2022, AL record) sits alone at the top. Behind him: Giancarlo Stanton (59 in 2017), Pete Alonso (53 in 2019, NL rookie record), Ryan Howard (58 in 2006), David Ortiz (54 in 2006), and Aaron Judge again (52 in 2017).

Whether Bonds, McGwire, and Sosa belong on the same list as Maris, Foxx, and Ruth — or whether Aaron Judge’s 62 is the de facto modern record — has been the central debate in baseball history for two decades. MLB itself has held to a single record book (Bonds’ 73 stands officially); some publications keep parallel pre- and post-testing leaderboards.

Background facts cross-referenced with the Wikipedia article on Barry Bonds and Pro-Football-Reference / Basketball-Reference public records.