Who is the only professional heavyweight boxer to have retired undefeated?
who is the only professional heavyweight boxer to have retired undefeated
FreebaseQA-train-3167.P0 FreebaseQA-train-3167.P1
boxer boxer
boxing boxing
m.01cgz m.01cgz
martial_arts.martial_art.well_known_practitioner sports.sport.pro_athletes..sports.pro_sports_played.athlete
m.0148sl
rocky marciano
m.0148sl
rocky marciano