Does the SEC's oversigning make a difference? Part 1

The SEC allows teams to oversign.  That is, teams can sign more recruits than they can allow on to the team per NCAA regulations.  The question I'd like to know is whether this practice has a material effect a team's season success.

This chart shows the number of recruiting classes signed, by conference and by number of recruits signed.

The numbers above the Conference Name is the average number of recruits signed for every team in the conference from 2005-2012.

The numbers in the chart matrix indicate the number of recruiting classes in a conference with a given number of signees.  For example, The SEC has a 7 in the cell for 'SEC' and '32'.  This means that in the SEC from 2005-2007, there were seven recruiting classes that signed 32 recruits. 

What does this mean, then?

The average number of recruits for the SEC was 24.8 per team, per season.  The next highest average was the Big12 at 23.4 recruits per team, per season.

A simple t-test on these two datasets indicates that there is a statistically significant difference between the average number of SEC recruits per class and the average number of Big12 recruits per class.  It follows that the differences for all other conferences and the SEC are also statistically significant.

So, the conclusion to be drawn is that the policy of oversigning makes a difference in the number of recruits per season, per team. 

But does it make a difference on the field?  That question will be much more complicated to answer, but it's the topic of my next HuskerMath blog post.