Andrew McGilligan | Out of WriteField
Defense wins championships.
It’s an adage drilled into the minds of football fans for decades, but what if we’re looking at defense the wrong way in this era of the NFL.
Rule changes have led to increased scoring and the play at the quarterback position is staggeringly great at the moment. Despite changes to the game, we still evaluate defense the same as 20 years ago.
On ESPN radio Friday morning, Herm Edwards spoke about the defensive numbers that are more important in today’s NFL than the usual rankings based on total defence.
On most NFL websites, the major categories – at least the ones that pop up when you go to the stats page – are total defence (which amounts to yards allowed per game) and a breakdown of rushing and passing yards allowed.
It would make sense that the team that allows the least amount of yards would therefore have the best defence, but the most basic premise of football is to end the game with more points than your opponent. In this sense, the team that limits the opposition’s chances to score (takeaways, ie. interceptions and fumbles recoveries) and allows the fewest points should be crucial factors when ranking defences.
The top 10 defences – based on total defense – for the regular season, as per the numbers on NFL.com, shows only six of the top 10 teams had a winning record. Four of the teams remaining in the playoffs were among the top 10 in total defense while the four others finished 11, 17, 24 and 25.
However, looking at scoring defence and takeaways tells a much different story.
When it comes to the teams who allowed the fewest points per game, six of the remaining playoff teams are in the top 10 with the other coming in at 11 and 12. As for takeaways differential (the team that created more turnovers than it allowed) seven of the teams remaining ranked in the top 10 while the other was ranked 19th.
So what does that mean for this weekend’s playoff games? Here are the defensive rankings taking into account total yards allowed, turnover differential and scoring defence. With eight teams remaining, each squad was given a number of 1-8 in all three categories with the lowest score equaling the best remaining defense:
2. San Francisco
6. New England
7. Green Bay
This is in stark contrast to the rankings at the end of the regular season. Here’s how NFL.com ranked the teams in terms of total defense:
2. San Francisco
5. Green Bay
8. New England
The numbers change even more dramatically if the teams are ranked using scoring defence and takeaway differential as the only two determining factors:
T-2. New England
4. San Francisco
8. Green Bay
So given the different ways of looking at things, what’s the overall impression of the defenses lining up this weekend. The first point is that the best remaining defensive squad is the Seahawks. Second point, the Broncos defense is somewhat overrated given they’re the only team with a negative turnover differential (-1) remaining in the playoffs and Denver’s ranking slides when other factors besides yards per game are considered.
The third point to take from this is New England gives up a lot of yards, but limits opponents in other ways such as turnovers. New England is +25 in turnover differential and created the second most turnovers on defence with 44.
Yards per game are an important stat, but it’s not truly indicative of an overall defense. More than one factor is should be considered when ranking teams, with scoring defense and turnover differential high on the list.