Matt Olson sets an all-time home run record

Oakland A’s first baseman Matt Olson hit his 39th homer of the season on Friday, and he’s got two games left to reach 40. In Oakland history, there have been 10 seasons of 40+ dingers by six different players.

Regardless of whether he reaches that milestone, Olson already set a piece of MLB history in the power department. Of his 39 long balls, 22 of them came against left-handed pitchers, which is the most ever on record by a left-handed hitter. Only two right-handed batters have hit more.

• 25: Dick Allen, PHI, 1966 (righty)
• 25: Cecil Fielder, DET, 1990 (righty)
• 22: Matt Olson, OAK, 2021 (lefty)
• 21: Ken Griffey Jr, SEA, 1996 (lefty)
• 21: Ken Griffey Jr, SEA, 1998 (lefty)
• 21: Barry Bonds, SFG, 2002 (lefty)

Further down the list, lefty Babe Ruth topped out at 19 homers off southpaws in his famous 1927, and so did lefty Reggie Jackson while with the Yankees in 1980. In A’s franchise history the lead by any batter is 16, held by Jackson in 1969 and righty Mark McGwire as a rookie in 1987; that same ‘87 season, righty Jose Canseco hit 15.

There is a bit of an asterisk attached, though, as some play-by-play records from the past are incomplete. In particular, in 1949 lefty Stan Musial hit 36 long balls, and 19 are credited against lefties, but only 11 are credited against righties with six more unaccounted for. Looking through what box scores are available, it appears at least three of those six came against southpaws, and possibly as many as five, pushing his unofficial total into the 22-24 range. (Update: It appears Musial hit 22 that year, based on HR logs.)

As for Olson, his indiscriminate power display comes in an era of magnified attention on platoon splits. The All-Star slugger has hit righties and lefties nearly equally well this year, making it impossible to neutralize him with a specialist reliever matchup, and in fact he has more dingers against lefties. That ability to blast everybody, plus an enormous reduction in his strikeout rate, are two leading factors in a career-best campaign that should earn him some recognition in MVP voting.

When Olson comes to the plate, he’s a threat no matter who is pitching. In all of MLB history, no lefty batter is known to have ever hit more homers off lefty pitchers in a single season.