Archive for August, 2007

The New Kickoff Rule

Friday, August 17th, 2007

There has been a lot of speculation by coaches and the media about the effect of the new rule in college football that moves the kickoff from the 35-yard line back to the 30. It seems that most coaches believe the change will have a significant effect on the game. However, at least one person in the media believes the the predicted impact is overblown.

Most of the talk about the new rule has centered around two expected effects:

  • More returns and less touchbacks
  • Longer returns and more returns for touchdown

Behind cfbstats.com I have a database that contains the details of every play, including kickoffs, for the 2005 and 2006 seasons. We can look at detailed data to see how kickoffs from the 30-yard line, which would have occurred because of penalty, impacted play the past two seasons. For the purposes of this examination, no onside kicks are included in the data.

A cautionary note: The sample size for kickoffs from the 30-yard line is small compared kickoffs from the 35. So while the data presented below is interesting, I’m wary of predicting what will happen in the 2007 season by comparing the numbers from the 30 and the 35.

More returns and less touchbacks

There’s not much debate about this. The general consensus is that more kickoffs will land in the field of play than before, resulting in more returns and less touchbacks. Urban Meyer’s staff reviewed game tapes and determined that the average kickoff would land at about the 9 yard line, while another study based on spring practices observed a range from the 8 to 12-yard lines.

The open question is how many more returns (and less touchbacks) will occur because of the new rule. The following table shows the average landing position and percentage of touchbacks for kickoffs from the four most frequent kickoff starting lines in 2005 and 2006.

Kickoff Start # Kickoffs Kickoff Land Avg. Touchbacks Touchback%
50 128 3.45 107 83.6%
35 14,496 5.56 4,334 29.9%
30 160 8.78 14 8.8%
20 282 19.55 3 1.1%
Total 15,066 5.83 4,458 29.6%

Kickoffs from the 30 resulted in 21.1% less touchbacks than kickoffs from the 35. If this difference holds for the 2007 season, that would be about two more kickoff returns per game since the average game has just over 10 kickoffs.

Kickoffs from the 30 resulted, on average, with the ball landing at the 8.78 yard line, which was 3.22 yards further into the field of play than kicks from the 35. That’s close to what Meyer’s staff predicted for the upcoming season.

However, it was not 5 yards further from the goal line as you might expect. This is probably because the kickoff data does not account for how deep the ball traveled into the end zone for a touchback, it only counts the yards to the goal line. So a touchback from the 35 did not just go 65 yards, it probably went 2 or 3 yards into the end zone, on average. On kickoffs from the 30, those extra yards are still in the field of play and are part of the kickoff data.

Longer returns and more returns for touchdown

According to Georgia’s Mark Richt, there will be a 10 to 15 yard change in field position to start the drive because kicking from the 30 yard line will give more space for the return. This seems to be the reasoning why some coaches are considering gimmick plays on kickoff returns and kicking the ball out of bounds.

This table shows the average return yards for each starting kickoff line and the average ending yard line of the return.

Kickoff Start # Returns Return Avg. Return End Avg. TD TD%
50 17 20.71 28.06 1 5.88%
35 9,310 20.35 26.99 72 0.77%
30 139 23.47 32.12 1 0.72%
20 259 20.85 39.88 3 1.16%
Total 9,725 20.41 27.41 77 0.79%

The returns of kickoffs from the 30 averaged 3.12 more yards than from the 35, and the average change in field position at the end of the return was 5.13 yards. This can be accounted for almost exactly by the start of the kickoff being moved back 5 yards. So there was not great impact on field position — over and above the given 5 yards — by kicking from the 30. It is also notable that the percentage of touchdowns is close when comparing returns on kickoffs from the 30 and 35.

It’s curious that the average return on kickoffs from the 35 was longer than kickoffs from the 20. It seems counter to Richt’s theory that having more room for the return will increase the length of the return. That could be because of the small sample sizes, or it could be that teams employed more strategies, like pooch kicking, when kicking off from their 20.

The data from the past two seasons does not point to big effect on the game from this new rule. However, I’m not willing to rule it out because of the small sample sizes. I do wonder about the impact of the new rule becoming a self-fulfilling prophecy. Many coaches are so concerned about the rule that they will implement changes in strategy and personnel on return teams starting with the first game, before the real effects are determined. These coaching decisions alone could be enough to affect the kickoffs and returns. Perhaps the coaches will take a wait-and-see approach.

I’ll be tracking the kickoff numbers each week throughout the 2007 season and posting them at cfbstats.com.

Thanks to The Wizard of Odds for his assistance in developing this entry.

3rd Down, 4th Down, and Red Zone Conversions

Wednesday, August 15th, 2007

Added 3rd Down Conversions, 4th Down Conversions, and Red Zone Conversions to the national and conference leader boards. I believe cfbstats.com is the only place you can find national leaders in Red Zone conversion offense and defense.

I’ve also added 3rd Down Conversions, 4th Down Conversions, Red Zone Conversions, First Downs, Penalties, and Turnover Margin for each team.

Defensive Statistics Added

Monday, August 13th, 2007

I’ve finally added defensive statistics to cfbstats.com. For the 2006 season, defensive statistics are available for each team and player, and also on the national and conference leader boards. They will also be available going forward for the 2007 season. I may go back and add them for the 2004 and 2005 seaons at some point, but it’s not a priority right now.

For each team, these defensive stat categories have been added: Interceptions, Fumble Returns, Tackles, Tackles For Loss, Sacks, and Misc. Defense. The same categories have been added for each player, if the player accumulated stats in the category.

For each national and conference team leader board, these categories have been added: Sacks, Sacks Allowed, Tackles For Loss, Tackles For Loss Allowed, Interceptions, Passes Defended, Fumbles Recovered, Fumbles Lost, Fumbles Forced, and Kicks/Punts Blocked.

For each national and conference player leader board, these categories have been added: Tackles, Sacks, Tackles For Loss, Interceptions, Passes Defended, Fumbles Forced, and Kicks/Punts Blocked.