How will the Northwestern offense fare under Trevor Siemian?

There's a saying that a football team with two quarterbacks has no quarterback. Kain Colter and Trevor Siemian proved that to be a myth in 2012 when they led Northwestern to a 10-3 season and Gator Bowl victory. But 2013 turned into Pat Fitzgerald's worst nightmare, which is probably why Northwestern fans have reservations about Siemian's ability to run the offense.

As Northwestern plummeted down the Big Ten standings so did Siemian's passer rating. During Northwestern's seven-game losing streak, Siemian threw seven interceptions and just three touchdowns, not the production you want from the most important position on the field. Now that Kain Colter has moved onto the NFL, Siemian is expected to be the lone man under center for NU.

Over the last two seasons, Siemian and Colter have both seen the field a lot. They have led their own drives, split snaps on the same drives and even graced the field at the same time with Colter at receiver. At this point, the plays, drives and games are becoming one big conglomerate in our minds. Separating how Northwestern performed under Siemian and how they performed under Colter cannot simply be done by memory. So, in order to determine how Northwestern will fare with just Trevor Siemian manning the offense, I decided to break it down.

Using stats from ESPN.com, I charted all of Northwestern's drives from 2012 and 2013 and separated them by quarterback. Of course, Siemian and Colter shared snaps on a lot drives, so if one of the two didn't play significantly more than the other on a single drive, or if Zack Oliver was in, the drive was tossed out. There were 16 of these in 2012 and 7 in 2013. I also tossed out all drives going into halftime or the end of the game since the drive was cut short by time.

From there, the drives were grouped by field position, because well, not all drives are created equal. The odds of scoring when you start at your own 25 are much different than when you start on your opponents half of the field. I broke field position down into three groups, inside the own 25, own 26-40 and beyond the own 40. Then I marked all of those drives that made it to the red zone and added the results.

The final results for 2012 and 2013 were at totally opposite ends of the spectrum, so let's start with the good. Here are Colter and Siemian's drive results from 2012:

There were only some minor differences between drives led by Colter and Siemian in 2012. Colter finished 7 percent more of his drives off with touchdowns than Siemian. Colter also moved the ball well from inside the 25, but his average drive distances with moderate and good starting field position were well below Siemian's averages.

Both quarterbacks had success in the red zone, finishing off 65 percent or more of red zone trips with touchdowns. Siemian did get some help from Colter though. Colter often subbed in at QB or receiver for just a couple plays to finish off red zone drives.

Siemian did a particularly good job of moving the 'Cats into scoring position when starting inside their own 40, scoring on over 38 percent of those drives.

Pat Fitzgerald trusted Siemian in the clutch too. Siemian led four 4th-quarter drives to take the lead that started inside Northwestern's own 25. Colter had four drives that secured victories with insurance touchdowns but half of them started in the red zone. When NU needed a long drive to get a W, Siemian was the man Fitzgerald put in the game.

Obviously, Northwestern struggled a lot more offensively in 2013 and the stats reflect it:

The average yards gained and scoring percentages dipped for both due to the plethora of issues NU dealt with in 2013. Colter battled through injuries, dropping his drive total significantly. An inexperienced offensive line struggled to pass protect and run block.  And Venric Mark was out a majority of the season, hurting the 'Cats' field position and play-calling options offensively.

Northwestern had all these problems, but the circumstances were the same for Colter and Siemian, and Siemian continued to lead longer drives than Colter. His average drive distance in every starting field position category was greater than Colter's. More of Siemian's drives ended with scores and again he was the man in the clutch, leading three 4th-quarter scoring drives to take the lead and two drives that padded victories with touchdowns.

The one place where Siemian faltered was the red zone. NU didn't punch it into the end zone on more than half of Siemian's red zone trips while Colter found paydirt on over 70 percent of his trips. Colter's overall touchdown percentage was 8 points higher than Siemian's as well.

Those red zone woes extremely hurt Northwestern in 2013. They got inside Ohio State's 20 six times last October but only scored three touchdowns. Overall, the 'Cats got in the end zone on just 52 percent of red zone trips. Colter's departure won't help NU improve in that department, but it would be incredible if those numbers got worse.

Overall, there's no reason to worry about Trevor Siemian running this offense solo. From a purely statistical standpoint, Siemian moved the offense just as well, if not better, than Colter in the last two seasons. Siemian led longer drives and consistently got NU into scoring position. He has a stronger, more accurate than arm than Colter too. The only place where Colter had a noticeable edge on Siemian was the red zone.

Trevor Siemian has his flaws. He hurries throws under pressure, evident in the nine picks he threw last season. He's not very mobile and often stares down his targets. With how last season turned out, this is the Trevor Siemian most Northwestern fans remember. 2014 provides Siemian the opportunity to make them forget all that.

Venric Mark is healthy once again. The offensive line had an entire year to gel. A deep wide receiver corps returns essentially everyone except Rashad Lawrence. And as the numbers show, Siemian moves the offense just as well as Kain Colter did. If Mick McCall draws up a winning formula for the red zone, the Northwestern offense won't be just fine under Trevor Siemian, it will be great.