CONCORD, N.C. - One bad race knocked three of NASCAR's biggest names to the bottom of the championship standings, and a repeat Saturday night at Charlotte Motor Speedway will put the trio on the verge of elimination. That's the harsh reality for Dale Earnhardt Jr., Brad Keselowski and six-time and defending NASCAR champion Jimmie Johnson. They combined to win more than a third of the races this season, and their title hopes could end before the third round of the Chase for the Sprint Cup championship.