Five questions heading into the second half of Cup season

The halfway point of the Sprint Cup season is in the rearview and the first 18 races have delivered the good (Denny Hamlin and Jimmie Johnson's five wins and Joey Logano's infamous quote, the bad (a gaffe at Sonoma that Marcos Ambrose will never get over and the down-right confounding (Jeff Gordon still hasn't won in 47 races; Ford last reached Victory Lane 21 events ago).

But it's also given us a number of burning questions in need of answers. Here's what the Racing Fan is dying to find out as the season heads from summer to fall -- and as a refresher, here were the questions dominating the series at the quarter pole.

1. Is Johnson readying for another run at history against challengers more intent than ever on ending his run? The four-time defending champion's season has been a roller coaster ride; his five wins are tied for the series lead, but five finishes of 30th or worse, which include four DNFs, are the most he's ever had at this point in the season.

Still, he answered any doubts that he could win in the spoiler era with back-to-back victories at New Hampshire and Sonoma and if the Chase began today he would have the top seed in the playoff, taking a tiebreaker from Hamlin with his second-place finish at Texas.

Until Johnson's season ends with anything other than a fifth title you have to consider him the favorite; really he's done nothing to convince anyone otherwise. But there's been a strangeness about Johnson's season; the mystique that separated him from his nearest competitors over the last four years -- a mind game that J.J. told me he has reveled in -- has seemingly disappeared and you could almost argue it's the reason for the rise in aggressive driving (more on that later) as the likes of Gordon and Kevin Harvick are taking more chances to increase their Chase resumes. With the pressure he'll face from a highly motivated cast of contenders, if Johnson does win a fifth Cup title, this may be the most impressive of them all.

2. Which darkhorse contender could win the title?Greg Biffle is enticing, having posted 10 top 10s, and so is Matt Kenseth, who has eight to his credit. But the one driver who should be looked at as one of the top threats to dethrone Johnson, and yet seems to be continuously lost in the discussion is Kurt Busch.

With two points wins -- to go along with his All-Star Race victory -- Busch has shown he can close the deal. But he sits fourth in the standings because of what makes him a true title threat: he's scary consistent. Over the last 15 races, the elder Busch has finished eighth or better a whopping 10 times -- the only drivers who have been better are Gordon and Harvick, who have each done it nine times -- and it was that same consistency that allowed him to win the inaugural Chase in 2004 as he came in sixth or better eight times.

3. Should we consider Dale Earnhardt Jr. a lock for the Chase? As SI's Lars Anderson so astutely pointed out, Little E left little doubt he can still drive in his dash to second in the Daytona 500. But it's been Junior's late push that has answered a more important question: whether he can regain the consistency that's been largely absent over the past two years.

A fourth-place finish in the season's second trip to Daytona -- a performance that Junior apologized to fans for because he didn't feel like he was competitive -- was his third top-10 finish in the last four races, pushing him up to 11th in the standings. But if there is one major problem surrounding Dale Jr.'s season, it's that he still hasn't made a serious charge at ending a winless drought that stretches back two years. He did deliver in the Nationwide race at Daytona, driving the No. 3 under the guidance of crew chief Tony Eury Jr., which makes you wonder if 1) The admitted pressure of driving his dad's number is exactly what he needs or 2) If it's Eury Jr., and not Lance McGrew, who ultimately should be in Junior's tower for the Cup races.

The remaining races play well into Earnhardt's chances of making the Chase; he's won four times at the sites of the seven remaining regular-season events (Atlanta, Bristol, Chicagoland and Michigan) and has six top-10s at Pocono. Junior should be in the running for something more this season than another Most Popular Driver award.

4. Who is to blame for Mark Martin's season? After finishing second to Johnson in the title race last season and racking up five wins, the ageless one is winless and stands outside of the top 12 with eight races left before the Chase. While he still has plenty of time to make a move, there's clearly something awry.

Is it the fact that Rick Hendrick messed with the No. 5's recipe, moving personnel over to the No. 88 to help Junior get his mojo back? Could it be the uncertainty of next season (Martin is still under contract, but Hendrick has promised to help new recruit Kasey Kahne find a ride for 2011)? Or maybe at 51, time is finally starting to catch up with Martin.

Whether the blames lies with outside influences is anyone's guess, but it's clear that even if Martin does get into the Chase, he's not the driver -- or the contender -- that he was last season. Could a rumored move to Red Bull Racing next season be the solution?

5. What's with all the aggression, and can it -- or should it -- be stopped? You can blame it, as many have and will continue to do, on the "Have at it boys" edict NASCAR handed down before the season, or you can chalk it up to drivers simply pushing the envelope. But there's no denying that there's been a certain attitude that's littered the field this season.

Tony Stewart says it all stems from a lack of respect and an inability of drivers to police themselves like they did in the past. "You just don't see as much of that as you used to and that was the way it used to fix itself and in my opinion, that is what it needs to get back to again," he said.

But is it really that simple, especially since one of the drivers who has been among the most glaring examples of this type of driving is a four-time champ (Gordon)? And while some may enjoy the widespread mean streak, just what is the style of racing going to look like when the races really start to mean something?

The problem, unfortunately, lies with NASCAR itself and vice president of competition Robin Pemberton, who coined that oft-used phrase in the preseason, because if the drivers aren't going to draw the line themselves, then it's up to the sanctioning body to do it for them. That may mean a hard-line decision, like parking someone for multiple run ins, even if it is one of the sport's biggest names (uh-hum, Gordon).

Chicagoland Pick

Tony Stewart. Smoke will strike fear in millions of summer-loving school kids with his back-to-school Office Depot paint scheme. A little early? Maybe, but it's all too fitting considering the way he's schooled the opposition in Joliet. In nine races, Stewart has won twice and snagged two finishes outside of the top 5. In desperate need of bonus points heading into the Chase, Smoke could deliver, though don't rule out Johnson checking off another track that he's never won at.