Finding the Winning Factors - Red Zone Efficiency

This week in the Finding the Winning Factors series, let's take a look at a stat that conventional wisdom tells us should lead to wins:  Red Zone Efficiency.  There are multiple ways to calculate this:  The NFL calculates it as RZ TDs / RZ Atts, and the NCAA calculates it as (RZ TDs + RZ FGs) / RZ Atts.  I think both of these are lacking, however.  One completely discounts FGs, which are still good on most occasions, and the other gives equal value to both TDs and FGs, which is also not quite right.  Teams should be rewarded for getting in the end zone.  So what's the best way to test this?  Here goes:

(RZ TD * 7 + RZ FG * 3) / (RZ Atts * 7)

Here's why it works:  Each time a team is in the Red Zone, a team has the possibility of scoring 7 points.  Each time a TD is scored, you did the best you can.  Each time a FG is kicked, it isn't worth as much as a TD (like in the game), but still counts for something.

Because of the way the NFL calculates Red Zone Efficiency, I had to use the Play by Play data to get all this data, which only goes back to 2001.  That means I'll be looking at 4,080 games over the past 8 years.  I did this calculation for every game, then found the overall average for a game.  I then went back and compared every game to this average, and found wins/losses based on being above or below average.  Here's some initial thoughts before getting to the data:

• The overall average over the past 8 seasons is 65.6%.  This means that teams score roughly 2/3 of the total points they could when they reach the Red Zone.
• For the first time in the series, the Colts did not lead the offensive category, with an efficiency of 71.3%.  Who leads the NFL?  The Chiefs at 72.1%.  As a Priest Holmes fantasy owner in the early part of this decade, I know why this was the case.  Their O-Line was massive, and Holmes was great in the Red Zone, which earned me some cash.
• Defensively, the Colts rank 16th at 66.1%.  This is the best ranking for the defense so far in the stats I've looked at.  The best defense?  The Ravens at 58.3%. 
  
• The range of Efficiencies isn't as large as I thought it would be.  There's only about a 12% difference between first and last.  This makes me think Red Zone Efficiency won't be as important as other stats, since teams are so bunched together.
• How well did teams do when they had Above Average Efficiency on Offense?  1284-880-2, which is a Win Percentage of 59.3%.  Better than .500, but lower than expected.  Having an Above Average Defense produces a record of 1158-754-2, which is 60.6%.  Slightly better than the Offensive numbers.  I really thought this would be higher.
• When both sides of the ball are Above Average, their records are 713-309-2, or a Win Percentage of 69.7%.  This is quite a bit lower than Adjusted Net Passing Yards / Play and Yards / Play, and proves my theory that Red Zone Efficiency isn't as important a factor to winning as other stats.
• The best game since 2001?  Week 7 of 2004, when the Chiefs went 8/8 in the Red Zone, with all 8 as Touchdowns, against the Falcons.  The worst game?  There were 8 different games where the team went 0/3 in the Red Zone, scoring no points at all.  These teams were 1-7 in those 8 games.
• The best game(s) for the Colts in this time span were Thanksgiving afternoon in 2004 against the Lions, and Week 12 against the Eagles in 2006, where the Colts scored 5 Touchdowns on 5 Red Zone trips.

After the jump you'll see the offensive and defensive numbers for each team, as well as Win/Loss records when going above/below the league average.  Click on the headers to sort.  Here's a link to the last 5 years worth of data.  There's not much of a difference, especially since it only took out 3 years worth of data.

Here are the Offensive and Defensive numbers...

Here are the Win/Loss records of teams when they go above/below average:

And finally, Win/Loss records when the offense is above average, and the defense holds the other team below average: