Each drive in a college football game can be assigned an expected point value based on where that drive starts. Those expected point values range from 0.76 points for a drive beginning 99 yards from the end zone to 6.34 for drives beginning one yard from the end zone. (TDs are assumed to be seven points).
By comparing the expected points for a team's drives to the actual points scored, we can get a picture of how efficiently a team capitalizes on the opportunities it has in a game. A team with a positive Drive-Point Efficiency rating is able to score more points than would have been expected based on their drive starting spots. Conversely, a team with a negative Drive-Point Efficiency rating scored fewer points than expected.
The actual rating is how many more or fewer points, on average, the team scored than the expected total points. For example, Oregon's Drive-Point Efficiency rating for Weeks 1 and 2 is 1.98, meaning the Ducks are averaging 1.98 more points per drive than would have been expected based on their drive starting spots.
This measure works for offense and defense, with the only difference in interpretation being that a negative Drive-Point Efficiency rating is better.
If a team scores on special teams or on a turnover it will help the offensive efficiency by increasing total points scored but not the number of drives.
When the offensive and defensive ratings are charted together, we get a picture of what teams maximized their opportunities on both sides of the ball. In all cases, further right and further up is better. The chart is interactive -- you can filter based on conference.