At 4-2 overall and still needing to finish .500 in its last six games to attend some random tire bowl, the North Carolina football team trots home to have coach Butch Davis sign the dotted line.

Is it refrigerator worthy or will there be no more Twinkies in their lunch boxes? The report card for year three of the Davis experiment follows after the jump.

Offense: Stats can be easily skewed, but when the offense ranks No. 115 out of 120 FBS teams in total yards gained it’s hard to point out many positives.

Of course, the offensive line is the easiest to blame. Injuries and unexpected departures were exposed in losses to Georgia Tech and Virginia. But the return of guard Jonathan Cooper against Georgia Southern seemed to make a difference in the running game.

The most contrasting difference between this season and last, however, is the wide receiver production. The departure of three receivers now playing in the NFL predictably exposed the passing game and has allowed opposing teams to stack the box and limit the rushing attack. Most noticeable is Greg Little’s lack of development into a deep threat. With only 230 yards receiving on the season and one touchdown, Little has far from filled the void left by Hakeem Nicks.

Freshmen receivers Jheranie Boyd (pictured) and Erik Highsmith flashed potential against ECU, but without consistent protection for T.J. Yates, opportunities for big plays have been limited. In 2008, Nicks and Brooks Foster has the ability to turn short receptions into game-changing plays.

Games against The Citadel and Georgia Southern showed what the offense can do when the quarterback is given time to throw. Improved play from the offensive line and development of the receivers are needed before this team can think about the postseason.

Grade C-

Defense: I’ll be the first to admit I was skeptical of how great this defense could be prior to the season. Yet here they are halfway through the season ranked No. 5 in the nation in yards allowed despite the shellacking in Atlanta against the Yellow Jackets.

But most surprisingly has been the performance by the secondary. Losing Trimane Goddard seemed like a steep barrier to overcome. After all, he intercepted seven passes in 2008 — good enough to tie for first in the nation. While interceptions have not come as easily this season, the Heels have allowed 125 yards per game through the air — good enough for third in the nation.

Defensive backs Deunta Williams and Charles Brown have been all over the field. Brown has a pair of interceptions and fumble recoveries through six games. Williams has also picked off two passes.

It starts with the front seven, though. The trio of linebackers dominated the headlines against Georgia Southern with each forcing a turnover. And the defensive line has been a monster for opposing offenses to handle, including the play of defensive end Robert Quinn (seven sacks).

Yet the lack of turnovers forced by this defense has been a big question mark after totaling 29 last season. Six of UNC’s 13 turnovers forced this season game against Georgia Southern. UNC’s offense wasn’t much better statistically last season (No. 92 in total offense) but the defense put the offense in position to win games. The defense must put points on the board or give the offense a short field to be truly dominant.

Grade A-

Special teams: Safety Da’Norris Searcy hasn’t been spectacular on punt returns … but he’s been solid. He returned a punt for a touchdown against The Citadel and UNC is No. 25 in yards gained on punt returns.

Punts, meanwhile, were an adventure to begin the season, but punter Grant Schallock progressed and averages a respectable 42 yards per punt through six games.

Kickoff returns and field goals have been the obvious tough spots for the special teams unit. UNC is averaging just under 20 yards per kickoff return — good for 99th in the nation and a striking difference from the Brandon Tate era. Kicker Casey Barth missed three of his eight attempts through the first six games.

Grade B-

How they’ll finish: It’s too early to figure out the 2009 version of the Tar Heels. Two of UNC’s four wins came against FCS opponents and really inflated the record. The .500 mark against FBS teams is the best predictor for how the season will unfold, and the schedule only gets more difficult.

Here’s the remaining schedule: Florida State, at Virginia Tech, Duke, Miami, at Boston College, at N.C. State.

I don’t see three guaranteed wins in those six games, but I also don’t see six losses. UNC should be competitive from here on out as the offense improves and heals. The best defense in the ACC is enough to give every team trouble as long as the offense refrains from shooting itself in the foot.

Expect the Heels to just qualify for the postseason by beating Florida State, Duke and N.C. State to finish 7-5.