[1][2] Exactly when Berkenstock first took up the game of baseball is unknown; the National Association of Base Ball Players, the first organized amateur league, was not founded until 1857, when he was 25.

: An Informal History of Baseball's Pioneer Era, 1843–1870, mentions him as a noteworthy player from amateur days, but doesn't specify when he began.

The New York Clipper newspaper described Berkenstock as "not a pretty player, being heavy and clumsy, but does good service (and) generally manages to hold any ball thrown to him."

On October 30, 1871, the Athletics met the Chicago White Stockings at the Union Grounds in Brooklyn, to decide the 1871 championship.

Berkenstock failed to get a hit in four trips to the plate (striking out three times), but recorded three putouts in the field, including the final out of the game.