Task: Explanation
Input (English): The Fitzsimmons vs Sharkey Heavyweight Championship boxing match between Bob Fitzsimmons and Tom Sharkey was awarded by referee Wyatt Earp to Sharkey after Fitzsimmons knocked Sharkey to the mat. Earp ruled that Fitzsimmons had hit Sharkey when he was down, but very few witnessed the purported foul. The fans at the December 2, 1896 fight in San Francisco booed Earp's decision. It was the first heavyweight championship fight since James J. Corbett, the prior champion, had retired from boxing the year before. The fight may have been the most anticipated fight on American soil that year. Question: What was the nickname of the reigning, retired heavyweight champion at the time of the Fitzsimmons vs. Sharkey Heavyweight Championship boxing match? Answer: "Gentleman Jim"
Output (English):  It was the first heavyweight championship fight since James J. Corbett, the prior champion, had retired from boxing the year before.