I think everyone guessed that the rule change that moved KO touchbacks to the 25-yard line would have an effect on the game. Today I looked at the degree to which that rule change has affected the game.
I used data from all drives from all games from 2005-present. I compared the averages of drives beginning with a KO and starting at the 20 yard line in 2005-2011 to drives beginning with KO and starting at the 25 yard line in 2012.
I looked at the following statistics sub-divided into how the drive ended (turnover on downs, end of half, FG, fumble, INT, missed FG, punt, safety, TD, and total)
Average number of plays per drive
Average TOP per drive
Average number of yards per drive
Number of drives reaching the red zone (subdivided into yes/no)
Average number of plays per drive
In 2012 the average drive was 5.89 plays, a decrease of 1% from the previous average. One thing I found particularly interesting is that the average number of plays in drives that ended in INTs decreased by 6%. This might indicate that coaches feel more comfortable with the extra five-yard cushion between them and the goal line and are willing to pass more closer to their opponents' end zone. The average number of plays of TD drives decreased by 4% as well.
Average TOP per drive
The average time of possession in 2012 on touchback drives decreased 7% over the previous average. The TOP of drives ending in INTs decreased 16% and the TOP of drives ending in a safety decreased and astounding 84% despite the drives starting 5 yards further from the endzone. The across-the-board decreases in TOP of drives is likely caused by more than just the drive starting location. I can only hazard a guess but it could be that the 'hurry up" offense has become more common in recent years, which would manifest itself here.
Average number of yards per drive
The average number of yards per drive was the least surprising to me. Although the aggregate average length of drives actually increased by 1%, this is easily accounted for in the increase in yards given up by safeties. In actuality, the decrease in TD drive lengths of 7% (5 yards) is closely mirrored in the length of drives ending in turnover on downs, FGs, and missed FGs.
Number of drives reaching the red zone
To me, the most important insight from this analysis comes from this statistic. While the overall number of drives reaching the red zone increased by only 4%, the percent change from 20% to 24% is 17%. This merits further analysis, as it could account for a significant change in scoring offense and offer some insight into perceived declines in defense. Based on this alone, there should be a corresponding increase in points scored in the red zone.
Summary
By moving the kickoff location to the 40, which increases touchbacks; and the touchback location to the 25, the NCAA has caused a number of expected and unexpected results. The most significant is the dramatic increase in drives reaching the red zone.
I used data from all drives from all games from 2005-present. I compared the averages of drives beginning with a KO and starting at the 20 yard line in 2005-2011 to drives beginning with KO and starting at the 25 yard line in 2012.
I looked at the following statistics sub-divided into how the drive ended (turnover on downs, end of half, FG, fumble, INT, missed FG, punt, safety, TD, and total)
Average number of plays per drive
Average TOP per drive
Average number of yards per drive
Number of drives reaching the red zone (subdivided into yes/no)
Average number of plays per drive
In 2012 the average drive was 5.89 plays, a decrease of 1% from the previous average. One thing I found particularly interesting is that the average number of plays in drives that ended in INTs decreased by 6%. This might indicate that coaches feel more comfortable with the extra five-yard cushion between them and the goal line and are willing to pass more closer to their opponents' end zone. The average number of plays of TD drives decreased by 4% as well.
Average TOP per drive
The average time of possession in 2012 on touchback drives decreased 7% over the previous average. The TOP of drives ending in INTs decreased 16% and the TOP of drives ending in a safety decreased and astounding 84% despite the drives starting 5 yards further from the endzone. The across-the-board decreases in TOP of drives is likely caused by more than just the drive starting location. I can only hazard a guess but it could be that the 'hurry up" offense has become more common in recent years, which would manifest itself here.
Average number of yards per drive
The average number of yards per drive was the least surprising to me. Although the aggregate average length of drives actually increased by 1%, this is easily accounted for in the increase in yards given up by safeties. In actuality, the decrease in TD drive lengths of 7% (5 yards) is closely mirrored in the length of drives ending in turnover on downs, FGs, and missed FGs.
Number of drives reaching the red zone
To me, the most important insight from this analysis comes from this statistic. While the overall number of drives reaching the red zone increased by only 4%, the percent change from 20% to 24% is 17%. This merits further analysis, as it could account for a significant change in scoring offense and offer some insight into perceived declines in defense. Based on this alone, there should be a corresponding increase in points scored in the red zone.
Summary
By moving the kickoff location to the 40, which increases touchbacks; and the touchback location to the 25, the NCAA has caused a number of expected and unexpected results. The most significant is the dramatic increase in drives reaching the red zone.
