No Rhyme or Reason

Position players (QB, RB, WR, TE) win you fantasy championships not special teams.  Defenses and kickers are too random from year to year. The Eagles led all defenses last year with 121 fantasy points in 2008 and the previous year they finished last with 55 fantasy points.    

Team Defense

Using Sports Illustrated's fantasy projections from 2004-2008:

• 15 of 50 defenses projected to finish in the top 10 actually finished in the top 10
• 22 of 50 defenses projected to finish 18^th or worse finished in the top 10

The primary reason defenses are so difficult to predict is the scoring of TDs.  Sure, you can look at a team's off-season moves, and make reasonable predictions about how many points they will let up week to week, or how many INTs or sacks they will record.  But TDs?  How do you predict fumbles in the end-zone?  INTS returned for 6? Punt returns for TDs?  Not even elite returners like the Chiefs' Dante Hall or the Bears' Devin Hester could maintain the magic from one season to the next.

Over the last four years ('04-'07 **can't use 2008 numbers cuz '09 hasn't happened)

• 28 of the 40 defenses or 70% that finished in the top 10 scored 5 or more TDs combined on defense/special teams the following seasons.
• The following season only 10 of those 40 defenses that finished in the top 10 or 25%  had 5 or more TDs combined on defense/special teams.

You can't accurately predict which teams are going to be scoring the most TDs.  Let others in your draft land the Steelers or the Ravens in the 12^th or 13^th round while you are playing better odds on young and unproven guys in situations whereby just one injury could catapult them into the limelight. 

Kickers

Kickers are slightly more predictable then defenses but still not worth drafting until the last few rounds of your draft.

Using Sports Illustrated top 10 projections vs. actuals from 2004-2008:

• Only 20 of the top 50 projected kickers (40%) actually finished in the top 10.
• While 25 of the actual top 50 kickers (50%) were projected as 15^th or worse.

So you're basically better off taking a kicker that SI ranks below 15^th than you are one they rank in the top 10.  The same can be said for any site, this is nothing against SI.   

It gets harder to predict the higher you predict them.

Looking just at the top 5 projections vs. actual from 2004-2008:

• 3 of the top 25 projected top 5 kickers ('04-'08) or 12%  have actually finished in the top 5
• While 15 of the top 25 actual kickers (60%) were projected 15^th or worse.

Point Differentials for Kickers and Defenses:

If the projections vs. actuals don't convince you, then maybe this will. 

Over the last 5 seasons - 2004-2008:

• The average difference between the 1^st and 10^th best defense is 34.6 points or 2.16 ppg
• The average difference between the 1^st and 10^th kicker is 27.4 points or 1.71 points per game

In summary, you have a better shot at landing a top 10 defense or kicker by drafting one projected to finish 15^th or worse over the last five years than you do one that is projected in the top 10.  And the point differential between the kickers and defense that you have such a low percentage chance of predicting is 34.6 pts (defense) and 27.4 pts (kickers) on the season.  Why not take fliers on guys like Robert Meachem, Austin Collie, whoever the 2^nd string QB is on the New England Patriots, or anyone that can find themselves in a great situation based on one injury, over taking the Steelers defense in the 13^th or 14^th rounds?  Kickers and Defenses should not be drafted until the last four rounds of your draft or last two rounds if you are planning to make pickups for your bye weeks.