Curses! There's been a lot of talk about those lately.

As the Red Sox battle the Yankees for American League supremacy, New England baseball fans are constantly reminded of the Curse of the Bambino.

Some believe the legendary hex is the reason Boston hasn't experienced a World Championship since 1918. There is a parallel here in NASCAR Nation. You might want to call it the Jinx on Jack.

Car owner Jack Roush began fielding Winston Cup teams in 1988. Similar to Boston's beleaguered baseball franchise since the Curse, Roush has come agonizingly close, finishing second four times, but has never won it all.

Perhaps the most painful loss was in 1990. That year Mark Martin won three races and led the championship standings from race 12 through 27.

After winning at Richmond, Martin's car failed post-race inspection. NASCAR ruled that his car had an illegal carburetor spacer plate. Martin retained the victory but was penalized 46 points. When the season concluded Martin and Roush were the championship runner-ups, finishing just 26 points behind Dale Earnhardt.

With six races remaining this season Roush is positioned to win his first Winston Cup crown. But the Jinx looms. Matt Kenseth leads the standings by 259 points. However, that lead was 436 points only two weeks ago.

An engine failure at Talladega and early crash last week in Kansas has suddenly exposed Kenseth to a challenge. Kevin Harvick, Dale Earnhardt Jr. and Ryan Newman are second, third and fourth respectively, separated by only 105 points.

"I've been saying all along that the thing is not over and you could have bad luck at anytime and things could go wrong at anytime," said Kenseth. "I realize how fast everything can change on you in this sport and we just have to keep our chin up and do the best we can. We still are in pretty good position for the rest of the year, we just have to go and run hard."

This week offers Kenseth an opportunity to return to form. Kenseth scored his first career victory at Lowe's Motor Speedway and has finished second in two of his last three races at the 1.5-mile track outside Charlotte, N.C.

Behind the efforts of Earnhardt, Richard Childress Racing has thwarted Roush's championship efforts twice (1990 & 1994). Once again RCR is the team threatening to spoil the party.

"We're digging, and Matt's having some bad luck," says Harvick, who qualified his RCR Chevrolet ninth for Saturday night's UAW-GM Quality 500. "If we keep knocking the lead off 80 or 100 points at a time, we're going to be in good shape in a couple of weeks.

"Right now, we're just going out and doing everything we can every week. Our cars are better, our pit stops more consistent, and that is helping everything come together. Down the stretch here, we're definitely racing a little harder because we've got something to shoot for. We just need luck to stay on our side and we'll see how things play out."

Earnhardt Jr. will turn 29 this weekend and you can probably guess how he'd like to celebrate. He's never won a points race at LMS, the track he calls home.

"I love the atmosphere and the track itself," Junior said. "We're always fast there, always a contender even if the numbers don't show it."

In eight previous Charlotte starts, Earnhardt Jr.'s best finish is fourth. He qualified 11th Thursday night and knows this could be a pivotal event in his championship quest.

"We can still move up in the points, but we can also fall back if we don't keep up the focus and intensity," Junior said. "We're having a great year, and I think we're going to finish strong."

The wild card in the championship chase is certainly Newman who has won three of the last five events. He has sliced 216 points from Kenseth's lead in the last two weeks alone. On Saturday night he'll start on the pole.

"When we get on a roll or when the team is doing well, it usually carries momentum both mentally and physically into the upcoming races," explained Newman after capturing his eighth Bud Pole of the year.

Kenseth's 259-point lead is far from safe. With six races remaining in 1992, Alan Kulwicki erased a 278-point margin to edge out Bill Elliott for that year's title. With history as their guide the contenders have reason to believe.

"If they continue to have problems like the last couple of weeks of the season, they might let a few of us back into the hunt," added Jimmie Johnson, sitting fifth in the standings 380 points back. "I still feel they are very much in control of the championship picture, but anything can happen."

With the challengers lined up to mount a charge there is reason to believe the Jinx on Jack could bite Roush Racing again this year. But as those who have lived with the Curse of the Bambino would say, Kenseth needs to cowboy up.

"As a group we've made some mistakes, especially me as the driver," asserted Kenseth. "We just need to go correct that and be smarter and do a better job and get back to running up front."

Mike Massaro covers NASCAR for ESPN and ESPN.com.