Jack O'Brien pugile
- combattimenti
- 12
- vinto
- 6
- perduto
- 2
- pareggiare
- 4
- Stato
- inactive
- Divisione
- -
- Debutto
- 1896-10-20
- Altezza
- -
- Arrivare a
- -
- Età
- -
- Nato
- -
- Morte
- -
- Nazionalità
- USA
| Data | Avversario | Ultimi risultati degli avversari | Luogo | Risultato |
|---|---|---|---|---|
| 1903-08-07 | Young Cahill | WDWLW | Lenox A.C., Boston | WIN Points |
| 1903-04-29 | Young Manning | L | Tammany A.C., Boston | WIN Technical knockout |
| 1903-04-13 | Jack Flavin | DWLDD | Sarsfield A.C., Boston | DRAW Points |
| 1902-02-18 | Dan Snyder | LDLWDL | Columbian A.C., East Boston | DRAW Points |
| 1900-04-19 | Billy Gardner | WWWDDL | Crescent A.C., Brockton | LOST Technical knockout |
| 1900-01-25 | Young Mack | debut | Crescent A.C., Brockton | WIN Technical knockout |
| 1899-09-12 | Jimmy Gorman | WWWWLW | Troy | WIN Points |
| 1899-08-12 | Jim Popp | WLDWDW | Hawthorne Club, Cheektowaga | WIN Technical knockout |
| 1898-11-15 | Jack Hamilton | DWDLWD | Manhattan A.C., Troy | WIN Points |
| 1898-10-18 | Jack Hamilton | WDWDLW | Manhattan A.C., Troy | DRAW Points |
| 1898-05-02 | Jig Stone | debut | City Point A.C., Boston | LOST Technical knockout |
| 1896-10-20 | Eddie Ford | DL | Wharton Hall, Philadelphia | DRAW Points |