Carl Edwards turns 300, and we're still not sure how good he'll be

No trajectory of a Sprint Cup driver's career seems harder to figure out than that of Carl Edwards. The driver of Jack Roush's No. 99 Ford Fusion has seen some of the highest highs possible, but he also endured extended lean periods.

This weekend the native of Missouri makes his 300th-career start at NASCAR's top level, all at the wheel of Roush's car. The milestone comes at Phoenix International Raceway, a track where Edwards ended one of those lean stretches with a win in 2010. He won again a week later in the season-finale at Homestead and remained the hottest driver on the circuit through the opening weeks of 2011.

Though he won just once, he nearly duplicated soon-to-be ex-teammate Matt Kenseth's feat in 2003 of winning the title with just a single win (both of their lone wins coming at Las Vegas). Of course, Tony Stewart denied Edwards, winning the championship in the first tie-breaker in series history.

This season, the 99 bunch has looked like a shadow of its 2011 form, with zero wins, three top-fives, and 13 top-10s with two races remaining. Last year, they had 19 finishes in the top-five alone.

Such ups and downs have marked the career of Edwards, one of NASCAR's great enigmas. One year he can be all but unstoppable, winning races and top-fiving his competition to death. Then the next, he is all but an afterthought, an also-ran struggling to stay relevant.

Take his 2005 campaign, his first full season in the Cup Series. The 99 bunch won four times (including a sweep of the races at the Atlanta Motor Speedway) and came within 35 points (under the old system, probably about seven-to-10 points under the current system) of beating Stewart for the championship.

The next year, Edwards went winless. In fact, after his fourth win of 2005 at Texas, his motorcoach driver Tom Giacci vowed not to shave until Edwards won again. He didn't win again until Father's Day 2007 at Michigan, by which time everyone referred to Giacci as "the Yeti of the garage area."

Edwards won twice more in '07, then enjoyed his best season in 2008. He won a series-high nine races (including three of the last four) and had a career-best 27 top-10s in 36 races, but a pair of miserable finishes in the Chase allowed Jimmie Johnson to beat him for the title.

He didn't see victory lane at all in 2009 and it wasn't until that penultimate race of 2010 where he finally broke back into the winner's circle.

Now he is in another similar winless drought, dating back to his victory in Las Vegas in March of 2011. At the time of that Vegas win, he had claimed three wins in his previous five starts and finished second in another. It seemed Edwards was ready to dominate like he did in 2008, but it simply didn't happen. He was nearly consistent enough to beat Stewart for the title, needing just one point, but they tied and Stewart's five wins earned him his third crown.

Edwards, meanwhile, still seeks his first. It won't come this year - he didn't come close to winning a race and by mid-summer seemed all but eliminated from the Chase picture altogether - and unless the team experiences a major turnaround, 2013 could be rough out of the box as well.

There are few personalities in the sport that are more endearing than Edwards. He is kind, outgoing, and even a little bit on the goofy side. There have been times in the past, though, where he wasn't quite so endearing. He's gone through highly publicized feuds with a number of drivers, including Stewart (long before their title battle), Kevin Harvick, Dale Earnhardt Jr., Kyle Busch, and most recently Brad Keselowski. Everyone remembers him intentionally spinning Keselowski and sending his car sailing upside down into the frontstretch wall at Atlanta in 2010, a year after the roles had been reversed - minus the intent - as they dueled for a win at Talladega.

Such contrasts in his personality led many folks to question whether he was genuinely a good guy, or if he was Eddie Haskell come to life as a race car driver. The truth, it seems, lay somewhere in the middle. He truly is one of the finest folks in our sport, but one who will push back - often to excess - when provoked.

Usually when a driver hits his 300th-career start, you can say for certain whether he is a contender or a pretender. You can tell if he's going to be one of our sport's all time greats, or a guy who has success in spurts but largely falls short.

So far, the jury remains in deliberation on the man known to the NASCAR Nation as "Cousin Carl" (thanks to beloved Sprint Cup veteran Kenny Schrader, who actually is one of Edwards' cousins). He has shown he has the potential to put it all together and be as unstoppable a force in our sport as Jimmie Johnson, Jeff Gordon, and others have been for an extended period of time. Whether he puts it all together and becomes that force, though, still remains to be seen.