Undefeated boxer Floyd Mayweather Jr. of the U.S. attends a news conference at the MGM Grand Hotel and Casino in Las Vegas, Nevada, in this file picture taken May 2, 2012. Mayweather Jr. was booked into a Las Vegas jail on June 1, 2012, to serve a 90-day sentence for domestic violence against an ex-girlfriend, a term that was previously postponed so the welterweight fighter could compete in a bout. REUTERS/Las Vegas Sun/Steve Marcus/Files (UNITED STATES - Tags: SPORT BOXING) © Bild: Reuters/STEVE MARCUS US-Topverdiener 16.05.2013 So gut verdienen US-Sportler Boxer Mayweather ist der bestverdienende US-Sportler des vergangenen Jahres. von: Martin Grath © Bild: Reuters/STEVE MARCUS File picture shows undefeated boxer Floyd Mayweath © Bild: APA/RHONA WISE USA BASKETBALL NBA © Bild: Reuters/DANNY MOLOSHOK Los Angeles Lakers' Kobe Bryant smiles after makin © Bild: Reuters/SCOTT MILLER Woods of the U.S. holds the trophy after he won th © Bild: Reuters/RICK WILKING Denver Broncos' Manning talks to coaches during th © Bild: Reuters/MIKE CASSESE New York Yankees' Alex Rodriguez reacts during Gam © Bild: Reuters/POOL NBA All-Star Kevin Durant of the Oklahoma Thunder © Bild: Reuters/RAY STUBBLEBINE New York Yankees' Derek Jeter answers questions at © Bild: Reuters/REBECCA COOK Detroit Lions' Johnson warms-up on the field befor © Bild: Reuters/MARK WALLHEISER File photo of Dale Earnhardt Jr. in Daytona Beach