Marciano's is just the HW record I believe.
Ricardo Lopez retired with a 51-0 record.
David Rodriguez, the great white dope! Ole David is currently sat at 35-0 (30 milkmen, a bartender, a cab driver, a 1978 bronze medal shotput thrower, a corpse, oh & a C- level club fighter/sparring partner from Jamaica that claims disability for having a sugar glass chin named Owen ''what a load of crap'' Beck) soon to be 36-0 and has no intentions of fighting anybody ranked in the top 50 so who knows, he's about 32 & fighting 4-5 barely top 150 ranked opponents each year so he'll probably end up around 70-0 before he is forced to retire & get back to sweeping the floors of McDonalds, either that or he'll be forced to retire as he can no longer even sell out the chicken sheds he fights in. Biggest fraud since that other undefeated, pillow-fisted, coward Sven Ottke.