<P> This is a list of world champions in professional boxing who retired undefeated, either during or after a title reign (s). It excludes current titleholders . Each champion's record is shown in the following format: wins--losses--draws--no contests . </P> <Table> <Tr> <Th> Boxer </Th> <Th> Record </Th> <Th> Weight class </Th> <Th> Title (s) </Th> <Th> Championship years </Th> <Th> Title defenses </Th> <Th> Notes </Th> </Tr> <Tr> <Td> Jimmy Barry </Td> <Td> 59--0--9 (2) </Td> <Td> Bantamweight </Td> <Td> World </Td> <Td> 1894--1899 </Td> <Td> 6 (3 draws) </Td> <Td> </Td> </Tr> <Tr> <Td> Joe Calzaghe </Td> <Td> 46--0--0 (0) </Td> <Td> Super middleweight </Td> <Td> WBO </Td> <Td> 1997--2007 </Td> <Td> 21 (WBO), 1 (IBF), 3 (The Ring, lineal), 0 (WBA, WBC) </Td> <Td> Vacated title to move up to light heavyweight </Td> </Tr> <Tr> <Td> IBF, The Ring, lineal </Td> <Td> 2006--2007 </Td> <Td> Unified WBO, IBF, and The Ring titles . Vacated IBF title to fight Peter Manfredo Jr. instead of #1 contender Robert Stieglitz . Vacated The Ring title to move up to light heavyweight . </Td> </Tr> <Tr> <Td> WBA, WBC </Td> <Td> 2007--2008 </Td> <Td> Unified WBO, WBA, WBC, and The Ring titles . Vacated titles to move up to light heavyweight . </Td> </Tr> <Tr> <Td> Light heavyweight </Td> <Td> The Ring </Td> <Td> 2008 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Kim Ji - won </Td> <Td> 16--0--2 (0) </Td> <Td> Super bantamweight </Td> <Td> IBF </Td> <Td> 1985--1986 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Mihai Leu </Td> <Td> 28--0--0 (0) </Td> <Td> Welterweight </Td> <Td> WBO </Td> <Td> </Td> <Td> </Td> <Td> Forced to retire from boxing due to an injury . </Td> </Tr> <Tr> <Td> Ricardo López </Td> <Td> 51--0--1 (0) </Td> <Td> Minimumweight </Td> <Td> WBC </Td> <Td> 1990--1998 </Td> <Td> 22 </Td> <Td> Vacated title to move up to light flyweight . </Td> </Tr> <Tr> <Td> WBO </Td> <Td> 1997--1998 </Td> <Td> 0 </Td> <Td> Unified WBC and WBO titles . Stripped of WBO title for saying he wanted to give the belt to his father . </Td> </Tr> <Tr> <Td> WBA </Td> <Td> 1998 </Td> <Td> 0 </Td> <Td> Vacated title to move up to junior flyweight . </Td> </Tr> <Tr> <Td> Light flyweight </Td> <Td> IBF </Td> <Td> 1999--2002 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Rocky Marciano </Td> <Td> 49--0--0 (0) </Td> <Td> Heavyweight </Td> <Td> World </Td> <Td> 1952--1956 </Td> <Td> 6 </Td> <Td> </Td> </Tr> <Tr> <Td> Terry Marsh </Td> <Td> 26--0--1 (0) </Td> <Td> Light welterweight </Td> <Td> IBF </Td> <Td> </Td> <Td> </Td> <Td> Forced to retire due to epilepsy . </Td> </Tr> <Tr> <Td> Floyd Mayweather Jr . </Td> <Td> 50--0--0 (0) </Td> <Td> Super featherweight </Td> <Td> WBC </Td> <Td> 1998--2002 </Td> <Td> 8 </Td> <Td> Vacated title to move up to lightweight . </Td> </Tr> <Tr> <Td> Lightweight </Td> <Td> WBC </Td> <Td> 2002--2004 </Td> <Td> </Td> <Td> Vacated title to move up to light welterweight . </Td> </Tr> <Tr> <Td> Light welterweight </Td> <Td> WBC </Td> <Td> 2005--2006 </Td> <Td> 0 </Td> <Td> Vacated title to move up to welterweight . </Td> </Tr> <Tr> <Td> Welterweight </Td> <Td> WBA, WBC </Td> <Td> 2006--2008, 2011--2015 </Td> <Td> 8 </Td> <Td> Retired at 49--0 in 2015; returned in 2017 for non-title McGregor fight and then retired again . </Td> </Tr> <Tr> <Td> Light middleweight </Td> <Td> WBA, WBC </Td> <Td> 2007, 2012--2015, 2017 </Td> <Td> </Td> </Tr> <Tr> <Td> Jack McAuliffe </Td> <Td> 30--0--5 (1) </Td> <Td> Lightweight </Td> <Td> World </Td> <Td> 1886--1893 </Td> <Td> 7--0--2 (0) </Td> <Td> </Td> </Tr> <Tr> <Td> Sven Ottke </Td> <Td> 34--0--0 (0) </Td> <Td> Super middleweight </Td> <Td> IBF </Td> <Td> 1998--2004 </Td> <Td> 21 </Td> <Td> </Td> </Tr> <Tr> <Td> WBA </Td> <Td> 2003--2004 </Td> <Td> </Td> <Td> Defended IBF title and defeated WBA champion to become WBA Super champion . </Td> </Tr> <Tr> <Td> Dmitry Pirog </Td> <Td> 20--0--0 (0) </Td> <Td> Middleweight </Td> <Td> WBO </Td> <Td> 2010--2012 </Td> <Td> </Td> <Td> Forced to retire from boxing due to chronic back injury . </Td> </Tr> <Tr> <Td> Harry Simon </Td> <Td> 30--0--0 (0) </Td> <Td> Light middleweight </Td> <Td> WBO </Td> <Td> 1998--2001 </Td> <Td> </Td> <Td> Vacated title to move up to middleweight . </Td> </Tr> <Tr> <Td> Middleweight </Td> <Td> WBO </Td> <Td> 2002 </Td> <Td> 0 </Td> <Td> Won WBO interim middleweight title in 2001 and the outright title in 2002 . Stripped of title at 29--0 when he was unable to defend it due to injuries suffered in a car crash . Had one more non-title fight before retiring . </Td> </Tr> <Tr> <Td> Pichit Sitbangprachan </Td> <Td> 24--0--0 (0) </Td> <Td> Flyweight </Td> <Td> IBF </Td> <Td> 1992--1994 </Td> <Td> </Td> <Td> Retired at 21--0 and then made a comeback . </Td> </Tr> <Tr> <Td> Edwin Valero </Td> <Td> 27--0--0 (0) </Td> <Td> Super featherweight </Td> <Td> WBA </Td> <Td> 2006--2008 </Td> <Td> </Td> <Td> Vacated title to move up to lightweight . </Td> </Tr> <Tr> <Td> Lightweight </Td> <Td> WBC </Td> <Td> 2009--2010 </Td> <Td> </Td> <Td> Vacated title to move up to light welterweight . Committed suicide after allegedly killing his wife in 2010 . All 27 fights were knockout wins . </Td> </Tr> <Tr> <Td> Andre Ward </Td> <Td> 32--0--0 (0) </Td> <Td> Super middleweight </Td> <Td> WBA </Td> <Td> 2009--2015 </Td> <Td> 6 </Td> <Td> Vacated titles in 2015 to move up to light heavyweight . </Td> </Tr> <Tr> <Td> WBC, The Ring, lineal </Td> <Td> 2011--2015 </Td> <Td> 1 (WBC), 2 (The Ring, lineal) </Td> </Tr> <Tr> <Td> Light heavyweight </Td> <Td> WBA, WBC, The Ring, lineal </Td> <Td> 2016--2017 </Td> <Td> 1 (WBA, IBF, WBO), 0 (The Ring, lineal) </Td> <Td> </Td> </Tr> </Table> <Tr> <Th> Boxer </Th> <Th> Record </Th> <Th> Weight class </Th> <Th> Title (s) </Th> <Th> Championship years </Th> <Th> Title defenses </Th> <Th> Notes </Th> </Tr>

Who has the best undefeated record in boxing
find me the text answering this question