By Erik Frenz (Twitter: ErikFrenz)
Cold, Hard Football Facts AFC Championship Game correspondent

It's been seven years since the Patriots tasted Super Bowl glory, but it could be just 17 days until they get another shot at it. 2011 wasn't supposed to be New England's year. The Patriots porous defense threatened to hold them short of their goal, but they are just two games away from overcoming it all. Standing in their way, though, is one of the best defenses in the NFL. 

Can an elite offense lift a team to championship glory, or does the old adage "defense wins championships" still hold true?

Here are just a few things we might learn along the way.

1. The Patriots defensive performance against the Broncos was a mirage, or a turning of the corner

The Patriots defense that took the field did one of three things during their bye week, before their game against the Broncos:
  1. Turned a corner.
  2. Beat up on an inferior opponent.
  3. Found a time machine and abducted the '85 Bears. Unfortunately were not able to do so before Super Bowl XX.
While No. 3 may not be a feasible option yet, the first two certainly are. If it was No. 2, the Patriots will be in for a huge treat as they face the league's No. 2-ranked Offensive Hogs (by contrast, they faced Denver's 23rd-ranked O-Hogs last week). Conventional wisdom might say that the Ravens simply ran the ball down everyone's throats, but their O-Hogs were a well-rounded unit which earned its ranking mainly by converting third downs and not giving up too many Negative Pass Plays on offense. 

There won't be any gifts this time around; the Patriots defense will have to get it done to some degree against the Ravens.

2. The No. 4 Passer Rating Differential is just enough, or not enough, to get by in January.

As those who are loyal to the CHFFs already know, a team that ranks in the top five in Passer Rating Differential has won 90 percent of all NFL championships since 1940. 

What's more, 58 percent of NFL championships have been won by a team that ranked either No. 1 or 2 in PRD. 

PRD is under siege this year, and at No. 4 in 2011, the Patriots are to PRD what Daniel Day Lewis was to Mohicans in 1992. The Patriots aren't the only ones left to be the saving grace in defense of PRD. All but two NFL champions since 1940 have ranked in the top 10 in PRD. The San Francisco 49ers rank sixth and Baltimore ranks eighth.

In this classic battle of strength vs. strength, it could be just as much the outcome of the battle of weakness vs. weakness that determines the war. Ray Rice is the key in the minds of most, but New England will greatly improve their chances to win if they are able to mitigate the damage in the passing game and eliminate big plays.

3. The Patriots are a rare breed, or a dying breed

With a win on Sunday, the Patriots can advance to their fifth Super Bowl in the past 11 years. Or they could fall short of their goal for the third time in three years.

No franchise in the free agency era has enjoyed as much success as the Patriots, and although a win will solidify their place in history, a loss will raise serious questions about the future.

How much longer does Tom Brady have? How many more times will Bill Belichick give it a go before he lets go? Win or lose, it's all on the table. But the winning or losing affects how we will talk about it this spring, summer and for years to come.