Oct 19, 2013; Knoxville, TN, USA; Tennessee Volunteers wide receiver Marquez North (8) catches a pass while being defended by South Carolina Gamecocks cornerback Ahmad Christian (4) during the second half at Neyland Stadium. Tennessee won 23 to 21. Mandatory Credit: Randy Sartin-USA TODAY Sports

If you gain four yards on every play, you’ll get a first down every three plays.

Vols running back Rajion Neal averages 5.2 yards a carry.

So that’s simple math right?

If only it were that easy.

Unfortunately for the Vols, that’s not how it works in the world of football.

In order to win, you have to be capable of picking up big chunks of yardage.

When the Volunteers have been successful this season, that’s something they’ve done well. Against South Carolina the Vols would have lost if not for Marquez North’s one-handed 39 yard reception.

While the Vols don’t necessarily need incredible one-handed catches to win games, they do need plays that account for 39 yards (or somewhere in that neighborhood).

When you pick up 39 yards on a play, it not only puts your team in a better position to score, but it also gives you the edge in the field position battle.

The field position battle is the game within the game that Tennessee was able to win against South Carolina, which in turn helped them to win the game.

Butch Jones knows the lack of explosive plays has been a problem for the Vols lately.

Jones: Explosive plays are critical to winning. You look at when we have had success moving the football, when we have been effective offensively, usually there is a byproduct of explosive plays and when we have struggled we haven’t had the explosive or what I call the big splash plays

One thing that’s hindered the Volunteers’ ability to make big plays is that Marquez North is the Vols’ only consistent deep threat.

If you’ve watched the Vols’ losses the past few weeks, however, you know that explosive plays don’t always have to come through the air.

Tennessee gave up several big plays to Auburn and none of them were passes — they were all runs.

Most notably they were runs from quarterback Nick Marshall.

With Josh Dobbs, the Vols now have a quarterback who’s able to make some of those same plays. He showed against Missouri and Auburn, with gains of more than 30 yards, that he’s perfectly capable of making big plays with his legs.

Regardless of how the big plays come, they have to happen or the Vols’ won’t make a bowl game.

The bad news for the Vols is that Vanderbilt has been very effective in limiting big plays this season.

Jones: That is the strength of Vanderbilt’s defense, they don’t allow you to have big splash plays. They haven’t given up big plays. They are skill in the backend. They are a senior dominated backend, they have played a lot of football, they have seen everything, they have played the best of the best. They play with great technique and they tackle. They have played a lot of football and they have a lot of experience and a lot of confidence. Again, we have to do a great job offensively, when we get one-on-one matchups we have to try and make them miss in space.

Butch Jones has had two weeks to prepare his team for their game against Vandy. The season is on the line as their bowl appearance hopes hinge on the outcome of this game.

The Vols have to find the magic they did against Georgia and South Carolina, or they’ll suffer the same fate they did a season ago.

This is a must win game for the Vols. If they fail to win, they can kiss any momentum they have left, goodbye.