Pass Efficiency Differential Margin (PEDM)
One statistic which is effective for predicting outcomes is the pass efficiency differential margin (PEDM). This metric is obtained by taking the difference between the offensive and defensive pass efficiency ratings for a team.
Pass efficiency (PE) is a measure of a team's passing ability, which is measured by four categories: (1) yards per pass attempt, (2) pass completions per pass attempt, (3) touchdowns per pass attempt and (4) interceptions per pass attempt. In the NCAA formula, four constants (i.e., 8.4, 100, 330, and 200) are used such that an average passer will have a rating close to 100. Pass efficiency is explained in more detail (here). Pass efficiency defense is calculated using the same formula, except it measures the PE of the opposing quarterback from week to week. Cumulatively, as opposing QB numbers are tallied each week, the pass efficiency defense is determined from the cumulative opposing QB numbers.
The Pass efficiency differential margin (PEDM) is the difference between pass efficiency (PE) and pass efficiency defense (PED).