The U.S. Open is one of golf's toughest tests almost every single year.
Since 2005, the eventual U.S. Open champion has not been able to shoot under par five times. Twice, the winner finished five-over par and won the tournament (Geoff Ogilvy in 2006 and Angel Cabrera in 2007).
However, a U.S. Open course can sometimes be beaten by the game's best. Tiger Woods posted perhaps his best tournament performance of all time when he shot 12-under par and beat the field by 15 strokes at Pebble Beach in 2000, and Rory McIlroy shot a U.