In 1902 alone, this guy beat Joe Walcott, Peter Mahar, Joe Choynski, Young Peter Jackson, Marvin Hart, and 27 other people without losing.
Great find R.Many thanks for posting this! O'Brien doesn't look marked up, which of course is a tribute to his defence.
Get your head round this: O'Brien sparred with an old Jem Mace as a young fighter, and he sparred with Joe Louis later in life! That is joining up quite a lot of boxing history!
According to CBZ, Mace Debuted in 1847 and Louis retired in 1951. That makes a span of 104 years! Is that a record?