The 49ers have lost their last two games at CenturyLink Field, and the defeats haven't been close.The combined score has been 71-16, Seattle.The Seahawks' home-field advantage now looms large as Seattle gets ready to host San Francisco in Sunday's NFC Championship Game.The combination of Seattle's loud and fervent fans, its 12th Man mystique and the terrific team built by head coach Pete Carroll has turned the Seahawks' home into the noisiest and most hostile stadium in the league for opposing teams. 49ers Fan PhotosOver the past two seasons the Seahawks are 16-1 at home. Since CenturyLink opened in 2002, the home team is 67-30, the second best in the NFL behind only Green Bay -- which has had consistently better teams over that span."It doesn't guarantee anything," Carroll told the Seattle Times last week. " But it certainly is more fun for us to play here than on the road. We have a tremendous connection with our fans and the 12th Man and CenturyLink. And all of that doesn't mean you are going to win. That just gives you the best advantage you can gain."But after taking his team through consecutive road playoff victories over the Packers and Panthers, 49ers head coach Jim...