With Formula One champion Nico Rosberg stunning the world by retiring less than a week after winning his first title, ESPN got to thinking -- is this the most shocking retirement in sporting history?So we put our heads together and came up with a shortlist to compete with the German driver. Read through the nominees below then vote for what you think was the most shocking.Sir Alex Ferguson (football)On May 8, 2013, with a 13th Premier League title in the bag, Ferguson told the world he was finally calling it a day as Manchester United manager. In an Old Trafford reign that spanned four decades, Ferguson also won two Champions League titles, five FA Cups and four League Cups, as well as the Cup Winners Cup, Super Cup, Intercontinental Cup and Club World Cup. United have not been the same since, winning just one FA Cup since the legendary Scots departure.Bjorn Borg (tennis)From teenage sensation to world No. 1, the Swede became the first male player to win 11 Grand Slam singles titles -- including five straight Wimbledon crowns -- during one of the toughest Open Era periods. Widely considered to be one of the greatest ever players, Borg shocked the world when he called time on his career aged just 26. He attempted a brief comeback during the early 1990s but the less said about that, the better...Rocky Marciano (boxing)The most famous of the handful of world champions who retired undefeated and resisted the temptation of a comeback -- and the only heavyweight world champion to achieve such a feat. The Brockton Blockbuster, who ended Joe Louis career in 1951, first won the world title in 1952 and retained it a further six times before he shocked the world in April 1956, retiring with a perfect record of 49 wins from 49 fights (with 43 knockouts). Aged just 32, the American wanted to spend more time with his family but his life was cut tragically short when he died in a plane crash on the eve of his 46th birthday.Bobby Jones (golf)Way back in 1930, the grandfather of golf became the first and only golfer to win the Grand Slam in the pre-Masters era, capturing the U.S. Open, Open Championship, U.S. Amateur and Amateur Championship in the same season. He immediately hung up his hickory-shafted clubs, deciding to compete only at The Masters -- a tournament he co-founded but, incidentally, never won.Michael Jordan (NBA)I just feel I dont have anything else, in myself, to prove. With that, Jordan walked away from the Chicago Bulls and the NBA. At the age of 30, the player who had done most to transform not only his franchise, but the league, called it quits, just four months after winning a third successive NBA title. Jordan would return -- and win another three-peat of championships -- but that doesnt alter just how seismic his original announcement was.Barry John (rugby)The pressures of living in a goldfish bowl convinced John to walk away from rugby union in 1972, aged just 27. His retirement came just a year after he had guided the British & Irish Lions to a series win over New Zealand, and he departed as Wales record points scorer. Johns elegant playmaking is still used as a blueprint for fly-half play in the principality.Barry Sanders (NFL)The Detroit Lions running-backs retirement was as much controversial as it was shocking. And it got very messy. Sanders was heavily criticised for retiring two years into a $35.4 million, six-year contract in July 1999. The Lions demanded that Sanders returned $5.5m of the $11m singing on bonus he was given, and sued him when he refused. Sanders was ordered to repay $1.83m -- a sixth of the bonus -- with the remaining bonus to be repaid over each of the three years Sanders had left on the contract provided he stayed retired. He did.ESPNs Alex Perry, Martyn Thomas, Rob Bartlett and Liam Grace contributed to this article. Air Max 97 Cheap Mens . "No difference at all," chirped U.S. roommate and linemate James van Riemsdyk. "Its still the same cranky Phil. Cheap Air Max 97 All Gold China . -- The proud fathers huddled near the Dallas Stars dressing room, smiling, laughing and telling stories while wearing replica green sweaters of their sons team. http://www.cheapairmax97fromchina.com/cheap-air-max-97-red-china/ . It was just business as usual for the Thunder at home. Durant scored 32 points and the Thunder beat the Bulls 107-95 on Thursday night for their eighth straight win. 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