The story is that the Minnesota Vikings have undergone profound improvement, and will soon emerge as a new football dynasty, winning several Super Bowls over the next 10 years. Led by a highly successful new coaching staff with somehow still something yet to prove, deep systemic change is underway, and along with masterful personnel upgrades from the front office, the team is ready to finally redeem the brand.

Even the owners have talked of the possibility of making it to Santa Clara this February.

There seem to be three schools of thought in response to this modern age Viking saga:

"Yes - I'm a believer. Let's win Super Bowl L. Skol!" "I see some improvements, but it takes many years to turn a football team around." "I've heard all of this before. Nothing much has really changed. I'll believe it when I see it."

Group 1 has clearly tasted too much of the purple Kool Aid. And who can blame Group 3 for their cynicism, after all of these decades of Cubs-fan-like disappointment?

Clearly the Group 2 response represents wisdom - a measured assessment of the realistic possibilities that the improved management and leadership is likely to effect over many years.

But are these assumptions correct?

Is there really a new system in place, or is it just so much lip service?

How much have things changed, and what can we expect as a result?

How quickly will all of this take effect, if at all?

How can we get past the PR stories?

Is there something measurable that we can look at?

The Question

The most common question I ran across in researching this piece:

Will the Vikings be able to put together a "Top 10 Defense" in 2015?

Of course, the "I'll believe it when I see it" crowd will have to wait, but the rest of us can get a glimpse at the potential performance of the unit by reviewing past performance, the changes effected by the new coaching hierarchy, and looking at change metrics to see if we can spot artifacts or indicators of continued improvement that support the idea.

Measurement

In 2014, the Minnesota Vikings ranked 11th in the league in points allowed per game and 14th in yards allowed per game, indicating "better than average" performance.

Unfortunately for the purposes of this discussion (and for discussing defensive unit rankings throughout the league), these are team statistics.

Yes, I said team statistics.

It is difficult to separate the performance of a defensive unit from the contributions or counteractions of other units on the team, especially with such simple metrics as Yards Per Game (aka "Total Defense") or Points Per Game (aka "Scoring Defense").

"Controlling the clock", or having an offense that is strong enough to maximize the time of possession can reduce the amount of time that opponent's offenses have on the field, and thereby reduce their points scored and yards gained per-game. Conversely, a poor offense can put an undue strain on the team's defense.

An example: A good ball-control offense can average time of possession of 32 minutes per game or more - this would mean that their defense would be on the field for less than 28 minutes. A defense that was on the field for 32 minutes per game, giving up 21 points and 350 yards per game would have to be considered better than defenses giving up the same amount of points and yardage while only on the field for 28 minutes (or 88% of the time as the first team).

Adjusting for time on the field gives a much better idea of the relative strength of the various defensive units in the league than do simple per-game statistics, giving us Points Per Minute (PPM) and Yards Per Minute (YPM) played.

Past Performance

In 2014 the Seattle Seahawks defensive unit led the league in both PPM and YPM. They were on the field for only 28 minutes and 34 seconds per game, and gave up only 0.57 points for each minute played.

The average time the Vikings defense was on the field in 2014 was 31 minutes and 15 seconds (of game time). They gave up 0.68 points per minute (PPM) on the field, which was 10th fewest in the league (with Cincinnati a distant 11th).

In this crucial respect, and though they did not come close to Seattle's performance, it can be seen that as a unit in 2014, they outperformed all recent Vikings seasons:

#1 (Seattle), Top 5 & Top 10 benchmarks are based on 2014 performance and included for reference only.

Note that the Vikings defensive unit's performance was already greatly improved since the regime change in early 2014. A 26% reduction in PPM brought the defense from one of the worst in the league to 10th. A further 12% reduction in 2015 would put them squarely in an elite (Top 5) status.

Yards Per Minute (YPM) is another important measure of a defensive unit's performance.

The Seahawks gave up 9.6 yards for each minute they were on the field in 2014 to lead the league in YPM.

The Vikings defensive unit gave up 11.04 YPM, which was 6th fewest in the league (a virtual tie for 5th with the Chiefs).

Again, though they did not come close to Seattle's performance, it can be seen by this measure that they were competitive with recent Vikings defenses that made the playoffs in 2008, 2012, and the all-important 2009 team that had a legitimate shot at the Vince Lombardi Trophy:

PPM and YPM analysis make it clear that the 2014 Vikings defense was considerably more competitive than is widely known - obscured only by a struggling offense.

Taken together, the above charts also show that the 2008-2010 Vikings defenses tended to give up slightly more points but less yards than did the 2014 defense. This was a strategy that particularly made sense in 2009, as it put the highly-explosive Vikings offense of that year back on the field sooner. For most of 2014, there was no explosive Vikings offense to put back on the field.

Reframing The Question

So back to the question on everyone's mind: Will the Vikings be able to put together a "Top 10 Defense" in 2015?

The answer, of course, is that they already had a Top 10 defensive unit in 2014.

10th in PPM.

6th in YPM.

Very good. Top 10. But not "elite".

The Super Bowl winning New England Patriots were 7th and 9th in PPM and YPM, respectively, in 2014. No better than the Vikes, except that they had a stronger offense (Top 10 vs. Bottom 10). So the Patriots prove that the Vikings defense is already good enough to contend, if the offense improves to Top 10 this year (a very big IF, which Part 2 of this series will address).

So how do the Vikings become recognized as a Top 10 D in 2015? Simple:

1) Continue the same level of defensive play as in 2014.

2) Improve the offense. (29:00 or better avg. time of possession)

4 out of the last 6 Super Bowls were won by teams sporting both a Top 10 offense and a Top 10 defense.

Only two had a truly elite defense. All but one had a Top 10 offense.

To truly improve our understanding of the state of the Vikings defense, we need to ask a different question:

"Can the Vikings defensive unit continue on its path of improvement to become a truly elite defense in 2015, entering the Top 5?"

The Elite

In 2014, four NFL defenses made the Top 5 in both PPM and YPM categories: Seattle, Buffalo, Detroit, and Kansas City. By this definition, these were the only "elite" defenses that year.

The reason that we need to take into account both PPM and YPM is that teams sometimes employ strategies that involve trading yards for points, or vice versa. The first approach favors teams with weak offenses, while the second can help teams that are good at winning shootouts. Most teams strike a fair balance between the two, but as we will see, some lean heavily to one side or the other.

Consider the following chart of the top defenses in the league last year. Note first that the Super Bowl was played between one team with an elite defense, and another team with just a "very good" defense.

Most teams' performance lies along a line of balance between PPM and YPM, though there is a slight league bias for minimizing PPM over YPM.

Denver and Arizona are great examples of outliers in this respect: the Broncos were ranked #3 in YPM, but #15 in PPM allowed. Similarly, Arizona achieved very close to the opposite: #4 in PPM, but #14 in YPM. Both teams elite in one respect, average in the other.

When asked why his defense gave up so many points and so few yards, Broncos Defensive Coordinator Jack Del Rio defended the approach, saying that they wanted to get their highly explosive offense back on the field ASAP. In other words, Denver's defensive unit regularly challenged opponents to "go big or go back to the bench" so they can get Peyton Manning & Co. back in play. Many 3-and-outs, interrupted by sporadic touchdowns.

The Cardinals did not have such an explosive offense in 2014 - just the opposite, they were in the bottom 10. In effect, they were counting on their defense to help their offense "burn time off the clock" by giving up small stuff, and stiffening near the red zone. Using an opportunistic approach (especially interceptions) to deny scoring, while giving up copious yardage. This is sometimes called a "bend-but-don't-break" defense.

An elite defense, on the other hand, can routinely get its offense back on the field quickly while simultaneously denying opponents scoring opportunities. Defensive units that make the Top 5 in both PPM and YPM have well proven themselves at achieving both goals, and can thus be considered truly "elite".

The Promise

We all know that Coach Zimmer has a reputation for architecting Top 5 defenses.

He has accomplished it before, in very quick order (from Bottom 10 to Top 5 by his 2nd year with the Bengals, for example).

The 2014 Vikings defense showed more of an improvement over 2013 than most people realize. This improvement, as we saw, can be characterized as merely restoring previous performance levels. Becoming a truly elite unit will probably require systemic and deep cultural change. And this is exactly the story we hear about what is happening during the off-season. But how do we know that this is actually taking place?

Anecdotal evidence can always be found (or manufactured) to support a story of systemic or cultural change within an organization. Stories about how "Kendricks is really adjusting well to the NFL", or that "Captain has a much better attitude about learning the system this year" for example, do not seriously inform. There is a certain audience that needs to hear such stories in order to promote ticket sales - especially when asking people to pay to sit outside in December in Minnesota.

Typically, cultural and systemic change initiatives are accompanied by metrics, identifying critical success factors on the path to the ultimate measurables (W/L, PPM, YPM, etc.). Verifiable key measures are then identified and implemented to monitor and assist in managing the change.

While we are not privy to the internal key measures employed by the Vikings organization, for our purposes, which is investigating the signs of change (instead of trying to manage it), we can use any objective and publicly available info to gauge the degree of commitment to change within the system and progress therein. This is akin to using a barometer to indicate potential weather changes. It will only give us evidence of change, not allow us to effectively manage its progress.

The Evidence

Smart, tough, fast are the apparent critical success factors in personnel selection now in place for the Vikings. Lip service has also been paid to wanting bigger players as well, but there is little evidence to support that this attribute is actually valued.

Of the 3 legitimate criteria, the easiest to objectively measure is "fast", based on published 40 yard dash times. (Wonderlics are controversial and "confidential", so not as readily available or applicable.)

Bear in mind that speed metrics tell only so much about a player - football is not merely a footrace. All else being equal, though (and for this purpose we can assume that it is), an examination of player speed will hopefully give us some indication about the extent of systemic changes occurring on the Vikings defensive depth chart.

For many years now, elite defenses have tended to field coverage personnel who are significantly faster than those fielded by average defenses.

Elite defenses in 2014 fielded coverage teams that were in the 63rd percentile. This means that, on average, the pass coverage players (CB, FS, SS, WLB, Slot) could outrun 63% of the players at comparable positions throughout the league. Analysis of these elite teams suggest that their coverage unit speed is trending to 71%, which really indicates more of an extreme upper limit of these teams' potential average speed in 2015 (They are unlikely to actually exceed 68%.)

Assumes Trae Waynes and Xavier Rhodes as starters in 2015

Notice the marked improvement from 2013 to 2014, which is again anticipated in 2015 over 2014.

Coverage personnel speed is one of the more traditional critical success factors in a pass-happy league.

More recently, though, overall team speed amongst the NFL's elite defensive units has begun to take precedence.

Beyond the "swarming defense" paradigm of many years ago, elite defensive systems have evolved to increasingly put speed to disciplined use throughout the defense, to good effect, and without much of the "over-pursuit exploits". The result? Even faster overall relative unit speed has been emphasized.

Elite defenses fielded players with speed ratings at the 69% relative to their respective positions throughout the league:

Assumes Eric Kendricks, Anthony Barr, and Trae Waynes as starters in 2015

Notice how, in less than two seasons, the Vikings defense has gone from relatively average in this respect, to what appears to be the fastest defense in the league!

It is a copycat league. And recent elite defenses are getting faster and faster, as everyone knows.

But these somewhat unbelievable charts do not speak of lip service to change, or blind adherence to some trendy approaches to defense.

As barometers of change, they instead show a perfect storm of rapid, purposeful strides towards radical, systemic change.

A sea change, if you will - something very different from what has come before - at least in Minnesota.

Signals of systemic change in personnel strategy do not come any clearer than the above charts.

The Vikings' new defensive system is apparently quite real, and progressing rapidly.

The data shows bold moves, not copy-cat moves. Leadership with a system based on unique parameters and assumptions. In other words, it shows Vision.

Further analysis shows additional examples of rapid and directed change:

The four elite defenses of 2014 had strong LB tandems that averaged in the 76th percentile for speed at their relative positions.

In 2014, the Vikings LB tandem averaged 34% in their respective positions - they were pretty slow.

In 2015, the Vikings LB tandem will average 94%, faster than all other such tandems, save Seattle (97%).

The average speed of expected 2015 defensive starters acquired since the regime change is 95%

The average speed of all additions added by the new regime that are expected to significantly contribute to the defensive unit within the next year or two is 87%:

Anthony Barr 98% Antone Exum 78% Trae Waynes 98% Scott Crichton(DE/DT) 73% Jabari Price 73% Danielle Hunter 97% Terence Newman 92% Eric Kendricks ILB 89%

The Answer

Mid-discussion, we asked a question:

"Can the Vikings defensive unit continue on its path of improvement to become a truly elite defense in 2015, entering the Top 5?

Apparently so. They were "knocking on the door" of the elite last year, and are apparently taking additional steps to move forward. It is comforting to know that the Vikings defense has already shown itself to be good enough to allow the team to contend, yet are not resting on their laurels.

Coach Zimmer has a track record of quickly building elite defenses - he has made it to the Top 5 in his second year before, with less resources and management support than he has now as Head Coach at the Vikings.

From what we have seen of the personnel decisions, it appears that Zimmer is leaning heavily on his prior experience, but also appears to be going further with it than he ever has. Whether this will eventually be enough to rival Seattle for #1 defense or not is sheer speculation at this point, though it is at best a difficult target for 2015.

In a copycat league, Mike Zimmer, George Edwards, and Rick Spielman appear to be doing something quite original with the Vikings defense.

Expect the Vikings to field an elite defensive unit this year.

If the offense improves enough to keep them off the field for a reasonable amount of time, they will even be recognized for it.

Part 2: Offensive Questions

Part 3: Answers