There has been a lot of debate as to when to draft a team defense in redraft leagues, and over the years I have seen the first one come off the board in single digit rounds while many times other owners take one with their very last pick. While it is clearly important to have at a minimum an average defense, many times the investment in a projected top defense is too costly. On many occasions, defenses get drafted similar to their rankings and production from the previous season. This got my thinking as to how NFL defenses have performed from one year to the next. I did some digging and here's what I found.

For starters, scoring for team defenses in fantasy football is SO VARIED that it would be impossible to define a standard scoring system. Reviewing the leagues that I personally play in, some give or take away points for yardage and points allowed (and some ignore either category). Many have different point values for turnovers, some count forced fumbles but not others, some count blocked kicks and special teams touchdowns, etc. The bottom line is that the scoring systems are all quite different. Because of that, the rankings for defenses in each league were somewhat varied, although rarely did a team have a radical difference in its ranking from one league to the next.

I elected to look only at NFL rankings for each franchise with regard to points allowed and yardage allowed. That's it--no turnovers, sacks, return TD, safeties scored, or anything else. In theory, if a defense minimizes the yardage and points it gives up, the odds are pretty good that it will do well fantasy wise. Getting accurate numbers for all the other categories would be a challenge, as few sites list all the information in an easily accessible format. In reviewing data in those other categories, I have concluded (without thorough review and analysis) that many times there is no rhyme or reason for which teams do well in those categories. Over the years, defensive TD, turnovers, safeties, and the like vary greatly from year to year. Sacks can often stay within a range, but for the most part many of these peripheral categories are difficult to predict.

I added each team's yearend ranking in points and yardage allowed for each of the past 10 seasons. The best a team could do in any season would be a score of 2 (ranking first in both categories). The worst a team could do in any season would be a score of 64 (ranking last in both categories). Four teams did have a year with a perfect score of 2. No team was so anemic to score a 64, but 11 teams did score 60 or higher. Again, in theory, dividing the number by 2 would give an approximate ranking for where the team might have ranked defensively in that given year.

To make things a bit easier to understand, I made a color-coded table to help people visualize how teams performed each year. Teams in the top 3 colors (red, orange, yellow) should be considered in the top half of the league (Top 15) and those in the other categories would be below average to poor.