7 things you need to know in college football

Here are the seven things you need to know from Week 3 of the college football season.

1. It's time to take Ole Miss seriously

Very seriously. They just went on the road against the second ranked team in the country, both in the AP poll and our own PFF Top 25, and came away with the victory. Grades have still to come in on that game, but we'd already seen the Rebels impress in their opening two games.

Quarterback Chad Kelly hit the heights with an incredible performance (+8.5), while the defensive line has proven to have a wealth of talent, and a lot of depth. Through the first two games of the season, a whopping eight of the team's defensive linemen had a positive grade.

They got a little bit of luck against the Crimson Tide, especially on the miracle touchdown where the snap was botched, and the ball bounced off an Alabama helmet, but make no mistake about it — this team has the talent to make a serious run in 2015.

2. Don't make Leonard Fournette angry

Staying in the SEC, let's just say that Auburn safety Rudy Ford might be regretting his trash talk about LSU running back Leonard Fournette. A 71-yard run on the Tigers' first play from scrimmage included Ford missing a tackle, but that was to be a theme for the day.

Fournette carried the ball 19 times against LSU's SEC rival and it wasn't just his 228 rushing yards that were impressive. The new Heisman front runner, according to plenty of people after Saturday, forced 11 missed tackles, more than once every two carries!

There's a lot of football left to be played this season, but Fournette made himself one of the headline players of the season with a dominant performance on Saturday.

3. The PAC-12 is wide open

In the North, Cal are the lone undefeated team, while Stanford was the only team with a conference win thanks to their victory over the USC Trojans on Saturday. No team has more than one loss, which isn't too surprising this early in the season, but all three of Oregon, Cal and Stanford have the talent to win the North, and the conference as well.

In the South, USC's surprising loss on Saturday has really opened things up. Considered the favorite by many, myself included, they've left the door open for the rest of the division. Arizona, Utah and UCLA, just, remain undefeated, while Arizona State and Colorado have got things back on track following a loss to open the season.

UCLA is now regarded as the team to beat by a lot of people, but they'll need more from quarterback Josh Rosen (-3.1), who has struggled each of the past two weeks.

4. Cody Kessler might not be the best quarterback in the country

In fact, right now he's not even the best quarterback in the PAC-12.

Kessler (+4.0) has had a solid start to the year, so it's not as if he's playing poorly, but his performance against Idaho (+2.8) is his only game through the first three weeks of the season where he finished with a grade of +1.0 or higher.

Meanwhile, Jared Goff (+15.1) is having an incredible start to the season, including a +5.2 performance against the Texas Longhorns on Saturday. Throwing the ball downfield has looked easy, and he completed four of the five passes he attempted of 20 yards or more against the Longhorns.

5. DeForest Buckner is a one-man wrecking crew

Sure, Georgia State aren't the toughest opponent for a big school like Oregon, but what DeForest Buckner is doing so far this season really deserves more attention.

He rushed the passer 29 times on Saturday, and produced two sacks, two hits and five hurries, while standing out against the run too. His grade for the year now stands at a whopping +22.9 through just three games. That includes a +6.3 performance against Michigan State where he registered three defensive stops.

We've now graded Buckner 18 times since we began grading every college football game, and he's graded negatively just twice, with his worst game coming in at -1.5 against Stanford last year.

6. Carl Nassib is, quietly, one of the best defensive players in the country

If you asked around for people to name the best edge defenders through the first three weeks of the season, names like Joey Bosa and Myles Garrett would likely be used early and often, and for good reason. But over at Penn State, Carl Nassib (+17.9) is having a very good start to the year.

His performance against Rutgers (+5.2) was his lowest graded game of the season so far, and he still came away with four hits and four hurries. Through three weeks he has five sacks, five hits and six hurries and one of the highest grades against the run too.

Not bad for a player who played just 210 snaps and had just one game where he graded at +2.0 or higher a year ago.

7. Christian Hackenberg continues to struggle

Penn State quarterback Christian Hackenberg continues to be mentioned as someone who will be in contention to be drafted number one overall in the future, and this week he continued his streak of negatively graded games, taking the total to 16.

We've yet to see the Nittany Lions signal caller produce a positively graded game, and that's definitely a continuing concern.

So far this season he has completed just two of the eight passes he has attempted of 20 yards or more downfield, with no touchdowns and an interception.