Harry Heilmann is one of the lesser known truly great hitters of the 1920’s. Heilmann played from 1914 to 1932, all but the last two seasons with the Detroit Tigers. He never got to play in the World Series and he never won an MVP award. He wasn’t known for his speed around the bases and his defense was only average. But there is no doubt that he could hit. His career Offensive WAR was higher than Carl Yastrzemski’s and Roberto Clemente’s and his career wRC+ was higher than Rickey Henderson’s and Duke Snider’s. With a career batting average higher than Tony Gwynn’s and a slugging percentage higher than Reggie Jackson’s, you would think we would have heard more about this outfielder who learned the game playing next to the great Ty Cobb.

His peak came during the Roaring Twenties, when Al Capone, Louis Armstrong and Babe Ruth became household names. But if Ruth was the Zeus of the Jazz Age, then Heilmann was the Apollo. He batted .364 during that time, second in baseball only to Rogers Hornsby. His wRC+ for the decade was 154, behind only Ruth, Hornsby and Lou Gehrig.

From 1921-1927 Heilmann was particularly dominant. Five times in that seven year stretch he finished in the top five in three of the biggest offensive metrics: wRC+, OPS+ and batting average. In 1923, he crossed the revered .400 mark, hitting .403. Only seven other players in the 20th century ever did the same.

Many baseball fans are aware that, beginning in 1920, a change in the physical production of the baseballs used in the majors resulted in an offensive avalanche. Home run numbers and batting averages skyrocketed. So it might be natural to dismiss Heilmann’s gaudy numbers as a result of the era. But take a look at the graph below. It shows Heilmann’s batting average compared to the League Average each year. To the right, you can see the same for Wade Boggs, albeit sixty years later. I use Boggs as an example because he had the highest batting average of any player for the decade of the 1980’s. In fact, Boggs finished twenty points higher than the second place player (.352 to .332).

What we can see from the graph is that Heilmann was often at least as far above League Average as Boggs was. In 1921, Heilmann batted .394, while League Average was .291. In 1923, he hit .403, some .119 higher than League Average (.284). In 1925 and yet again in 1927 he achieved the same .100+ interval.

Once you take a look at Wade Boggs, you see that yes, League Average was lower than in Heilmann’s time. But the gap between Boggs and League Average was incredibly similar to Heilmann’s: Boggs hit .100 or more above Average four times, the same as Heilmann. And the .119 gap that Heilmann achieved in 1923 was never matched by Boggs.

Yet another graph compares Heilmann to the all time batting average leader, Ty Cobb. This graph compares the two players by age. So we can take a look at how Heilmann compared to Cobb during their age 26-33 (typical peak) seasons. As you can see, he again matches up very favorably (though Cobb obviously sustained his greatness for much longer).

Heilmann currently ranks 7th all time in batting average (.342) and 27th in OBP (on base %). Assimilating various hitting metrics from several respected sources easily places him as one of the top 40 hitters of all time. He was elected to the Hall of Fame in 1952.