Without question, this has been Dale Earnhardt Jr.'s best season in Winston Cup racing.

He's been the closest challenger to points leader Matt Kenseth for most of the season, has shown a new maturity and talent level that proves without a doubt he's the late Dale Sr.'s kid, and has a great many more people predicting even further greatness -- and potentially several championships in the coming years -- for Junior and the No. 8 Chevrolet.

Junior's even borrowed a page from Kenseth's playbook, realizing that Winston Cup championships aren't just won with victories, but with race-to-race consistency. For, while Earnhardt Jr. has been a multiple race winner in each of the last three seasons, he, like Kenseth, has visited Victory Lane just once in 2003.

And making things all the more special? This is only Earnhardt Jr.'s fourth full season in Cup racing.

At this Sunday's EA Sports 500, Earnhardt Jr. will be going for an unprecedented fifth straight Winston Cup victory at Talladega (Ala.) Superspeedway, a streak that dates back to this same race two years ago (if you add in the Busch Series race he won there this past April, he's going for six straight wins at the track overall).

It's difficult enough for most just to win once at the high-banked 2.66-mile oval, the biggest, longest and arguably toughest on the Winston Cup circuit, but Earnhardt Jr. rewrites the history books each time he and the No. 8 Chevy roll through the gates at the Alabama racing shrine.

Earnhardt Jr. has led 432 laps in six career starts at Talladega, nearly one-third of all total laps in those events. And while each race has had a story of its own to tell, this past April's Aaron's 499 was perhaps Earnhardt Jr.'s greatest race ever, be it on a superspeedway, mid-range oval, road course or short-track.

All the odds were stacked against Earnhardt Jr. and the No. 8 in that race. He qualified respectably (13th), but was forced to start at the back of the field on race day when his team had to change engines.

Then, he had to make an incredible 15 extra pit stops to repair damage to the front of his car after being involved in a multi-car crash on just the fourth lap of the 188-lap race.

Incredulously, Earnhardt Jr. bobbed and weaved his way through the crowd during the ensuing 184 laps to take home the checkered flag. He was able to stay out of any more trouble, smartly chose where to pass and where to hold his ground, and drove a race that reminded of how his father would have done it.

Junior not only earned that win, but he did it in one of the most difficult ways imaginable. It was one of the most inspiring efforts Winston Cup racing has seen in a long time.

	Earnhardt Jr. swept the Talladega Cup races in 2002.

Fast forward a few months and, alas, not all is perfect in Earnhardt Jr.'s world.

With the hard crash and resulting brief period of unconsciousness Earnhardt Jr. suffered Sunday at Dover -- though he denies he ever lost consciousness -- there is some reason to be concerned about this coming Sunday's race.

Only a year ago after last fall's victory at Talladega, Junior finally came clean and owned up to racing for nearly three months while still suffering the aftereffects of a nasty concussion he received in a crash at California Speedway in April 2002.

Apparently being punch drunk during races was no big deal to Junior -- and some of his fellow drivers vilified him for his flippant attitude. He not only messed with their livelihoods, more importantly he messed with their lives by being so careless.

If a driver isn't 100 percent physically and mentally, even if your name is Earnhardt, you have absolutely no business being behind the wheel of a Winston Cup stock car, where the speeds can exceed 200 mph and the cars at times are separated by mere inches.

And Talladega happens to be the site of some of Winston Cup racing's most memorable wins -- and wrecks. If Earnhardt Jr. intends to win his fifth in a row at 'Dega, he hopefully will do so at 100 percent, not 80 percent or some other undesirable number.

Earnhardt Jr. is coming off a wicked wreck that saw him not only suffer a mild concussion but also suffer a sprained right foot. He has been cleared by NASCAR to race, but one can't help but wonder just what percentile he's operating at today, and what level he'll be at on Sunday.

Earnhardt Jr.'s press handlers have dubbed his quest for yet another Winston Cup win at Talladega as "the drive for five." Can he do it? Of course .... but not if he's at less than full health.

Dale Earnhardt Inc. has owned superspeedway racing the last three years, dating to Michael Waltrip's win at the same Daytona 500 in which Dale Earnhardt Sr. lost his life on February 18, 2001. Since then, Waltrip has won twice more at Daytona -- the July 2002 Pepsi 400 and this year's season-opening Daytona 500 -- while Junior has won his four straight at Talladega and once at Daytona (Pepsi 400 in July 2001).

That's a streak of eight wins in the last 11 superspeedway races. No other organization has even come close, past or present.

But there's also more motivation than usual heading into Sunday's race. DEI has struggled lately. Waltrip has failed to finish higher than 26th in his last five starts and wound up 42nd for the second time in that same period at Dover, dropping him out of the top-10 for the first time this season.

Junior, meanwhile, after holding down the No. 2 spot behind Kenseth for 17 of the last 20 weeks, dropped to fourth-place after his ignominious outcome at Dover. What's more, he's been mired in a minor slump of late himself: In the last six races, he's managed just one top-five and one other top-10 finish. The other four finishes have ranged from mediocre to terrible: 17th, 25th, 32nd (crash at Michigan) and 37th (at Dover).

Both teams and the organization as a whole need a strong showing Sunday from Junior and Waltrip. But for Junior, overcoming a slump is one thing; doing it right after suffering a concussion -- and any lingering fuzziness that may remain -- is a whole different ballgame. Hopefully, Junior is fit for the race. But if he isn't, perhaps he'll have learned enough of a lesson from last year's post-concussion imbroglio not to push it.

Jerry Bonkowski covers NASCAR for ESPN.com. He can be reached at Motorsportwriter@MSN.com.