Quitting at the top, Formula One champion Nico Rosberg shocked the world of motor racing Friday by announcing he was retiring at the age of 31, five days after earning his first world championship.I have decided to end my Formula One career. I had a very, very clear dream, that was to become Formula One world champion. I have achieved this childhood dream now and I am not willing to do that sort of commitment again, Rosberg said in Vienna.So I have decided to follow my heart, and my heart has told me just to stop there, to call it a day.Rosberg said he made the decision on Monday, a day after finishing second at the season-ending Abu Dhabi Grand Prix to clinch the F1 title.I am on the peak, so this feels right, he said.He wrote on Facebook of the difficulties he faced over a season that took a toll on people close to him: It was a whole family effort of sacrifice, putting everything behind our target.Rosberg had a strained relationship with Mercedes teammate Lewis Hamilton. They came up through the karting circuits to became fierce rivals in F1, constantly needling each other in the media. They dueled for the F1 championship for the last three years. Rosberg was runner-up to Hamilton in 2014 and 2015, but hung on this year to relieve Hamilton of the title in the final race.Rosbergs father, Keke, the 1982 F1 champion, said after watching his son in Abu Dhabi that the strain of fighting Hamilton was sapping him.I dont know how much its taken out of him, Keke Rosberg said on Sunday. Maybe he retires tomorrow.All observers thought that was a quip. Mercedes said on its website that Rosberg will stop racing in Formula One with immediate effect.Hamilton said he was not surprised by his teammates decision.Im probably one of the only people that it was not a surprise to, Hamilton said. He later added: Will I miss the rivalry? Of course.The three-time champion said he would help Mercedes look for a replacement.Im interested to see who would want to be my teammate, and respect anyone that would want to, Hamilton said.Rosberg said it had been his dream, my `one thing to become Formula One world champion. Through the hard work, the pain, the sacrifices, this has been my target. And now Ive made it. I have climbed my mountain.In an online video, the German said: Im not willing to do it again next year.Rosberg won 23 races (tied for 12th all-time) and 30 pole positions (8th) from 206 races since his debut in 2006.He began thinking of retirement after winning in Suzuka in early October, when the destiny of the title was in my own hands.Mercedes chief Toto Wolff paid tribute to Rosberg for making a brave decision.He has chosen to leave at the pinnacle of his career, as world champion, having achieved his childhood dream, Wolff said. The clarity of his judgment meant I accepted his decision straight away when he told me.Rosberg is the first reigning champion to retire since Alain Prost in 1993.If you accomplish your goal, then theres no reason to stay around, track and fields athlete of the year Usain Bolt said upon hearing the news in Monaco.Clearance NMD Ireland Outlet . Cote was eligible to become a free agent Feb. 15. Cote helped running back Jon Cornish run for a league-high 1,813 rushing yards en route to being named the leagues most outstanding player. Wholesale NMD Ireland Online .500 on the season. The Jets are now 0-5-1 in the second game of back-to-backs. The game started the same way the Vancouver game started the night before, with the Jets taking the first two penalties of the game and killing off the first, but the Oilers getting on the board first, scoring on the second man-advantage. http://www.wholesalenmdireland.com/ . -- If this was Aaron Gordons final home game at Arizona, and it almost certainly was, then he went out in style. Discount NMD Ireland . -- Running backs Darren McFadden and Rashad Jennings were back at practice for the Oakland Raiders on Wednesday despite being hampered by hamstring injuries. NMD Ireland ., and Rudi Swiegers of Kipling, Sask., took sixth spot on Saturday in pairs at the NHK Trophy ISU Grand Prix figure skating competition.DETROIT -- Mike Pelfrey described his performance as terrible over and over in a harsh postgame assessment that few would disagree with.Pelfrey allowed four runs in the first inning and didnt make it out of the second Saturday night, putting the Detroit Tigers in an early hole in their 8-4 loss to the Kansas City Royals.I felt like Id never thrown the ball before. That was embarrassing, Pelfrey said. I didnt have any idea where the ball was going, as everyone could probably tell.Ian Kinsler homered for Detroit, but the Tigers were facing a significant deficit before they even came up to bat for the first time. Pelfrey (2-9) allowed five runs, four hits and four walks in 1 2/3 innings.I was terrible. Didnt get ahead, and half the guys I faced either got walks or hits. I was terrible, Pelfrey said. This games on me. I put the bullpen in a bad spot, I put the offense in a bad spot, and I take full responsibility for it. I was terrible. I got what I deserved.Salvador Perez singled, doubled, scored a run and drew two of Kansas Citys seven walks. Every hitter in the Royals lineup scored exactly once except right fielder Paulo Orlando.Danny Duffy (5-1) allowed four runs and six hits in 6 1/3 innings for Kansas City. He struck out seven and walked one.Pelfrey actually retired the first batter of the game, but the next six Kansas City hitters reached base. Alex Gordon opened the scoring with a bases-loaded single, and Pelfrey then hit Orlando to force in another run. Cheslor Cuthberts RBI single made it 3-0, and Christian Colon brought home another run with a groundout.After allowing a single and two walks in the second, Pelfrey was pulled with the bases loaded and two outs. Reliever Dustin Molleken immediately threw a wild pitch that made it 5-1.We were hoping to get some momentum after winning yyesterday in our first game back, but the expression is that momentum is your next starting pitcher and Pelf just had an off day, Tigers manager Brad Ausmus said.ddddddddddddKinslers two-run homer in the third cut the lead in half, but the Royals added three more runs in the fifth on RBI singles by Colon, Jarrod Dyson and Eric Hosmer.Royals closer Wade Davis pitched a perfect ninth inning in his return from a strained forearm. Davis was activated from the disabled list before the game, and Kansas City went ahead and used him in a non-save situation.WAITING HIM OUTThe Royals arent a team that walks much, but they adjusted when it became clear Pelfrey was having control problems.We put in some good at-bats there in the first inning, Hosmer said. A lot of guys toned down the aggressiveness a little bit, wanted to see some pitches.TRANSACTIONThe Tigers optioned OF Steven Moya to Triple-A Toledo after the game. Theyll have OF Justin Upton back from the bereavement list for Sundays game against Kansas City.TRAINERS ROOMRoyals: Davis hadnt pitched since June 30. ... Manager Ned Yost said OF Lorenzo Cain (left hamstring strain) might go out on a rehab assignment next week.Tigers: LHP Daniel Norris (right oblique strain) is expected to begin rehab work with Toledo next week. ... RHP Jordan Zimmermann (right neck strain) said hell probably throw a bullpen session Monday.UP NEXTRoyals: RHP Yordano Ventura (6-7) takes the mound in the series finale Sunday. Hes 6-0 with a 3.27 ERA in his career against the Tigers.Tigers: Rookie RHP Michael Fulmer (9-2) tries for his 10th consecutive start allowing one earned run or fewer.---Follow Noah Trister at www.Twitter.com/noahtrister ' ' '