[5] In one of his first fights on May 14, 1902, Berger defeated Andy Gallagher in a third round technical knockout at the Olympic Athletic Club in San Francisco.

[1] Berger defeated Jack Joyce on July 10, 1902, in a four round points decision at the Mechanic's Pavilion in San Francisco as part of the Aerial Rowing Club.

Berger seemed to land more blows, taking the Pacific Coast Championship, and Joyce did not appear to have trained adequately for the event.

[6][1] Berger defeated George Sullivan in a fourth round knockout at Mechanic's Pavilion in San Francisco on January 19, 1904.

The New York World and Philadelphia Inquirer came out heavily for Berger, but the Washington Post considered the match a draw.

The match, due to its large audience and the excitement it generated, was considered to be the most noteworthy of Berger's professional career.

[13] In another important bout, Berger took a beating and lost to Al Kaufman in a tenth round technical knockout on October 31, 1906, in San Francisco's Dreamland Pavilion.

Kaufman's constant jabs, particularly with his left during the infighting, tired Berger till his seconds were forced to concede in the tenth.

After his boxing career, he became a successful businessman, holding interest in a high end clothing store in San Francisco, run by his two brothers Nat and Maurice.

[17][18][19] He managed Jeffries for his fight in Reno, Nevada against black heavyweight champion Jack Johnson on July 4, 1910.

As quite a profitable affair, the "Fight of the Century", drew 20,000, and fetched over $100,000 to divide between Berger, various trainers and support personnel, and Jeffries, whose cut was $60,000.

Perhaps a greater success at the business of refereeing and promoting boxing than competing, he died with a fortune equivalent to a million dollars today.