Guest columnist Zachary O. Binney looks the effects of the removal of the "Probable" designation from the NFL's official injury reports.
18 Apr 2014
by Scott Kacsmar
Is it safe?
There was no need for someone like Dr. Christian Szell, a Nazi war criminal played masterfully by Laurence Oliver in Marathon Man, to grill NFL commissioner Roger Goodell over making the game safer for players. A growing number of lawsuits from ex-players can put a scare in even the shrewdest businessman. The league had to push a stronger safety initiative and one aspect of the game that's easier to control is the kickoff.
For some fans, the kickoff was one of the most exciting plays in football. For the NFL, it was viewed as a harbinger of injury where some of the most high-impact collisions took place. The NFL's solution to reduce those hits was as simple as moving the spot of the kickoff to the 35-yard line rather than the 30. That rule change was put into effect starting in the 2011 season, ensuring that our weekly NFL Red Zone viewing begins with a touchback montage.
Did it work? After one season the NFL's competition committee boasted that concussions were down 40 percent on kickoffs in 2011. Earlier this year, NFL injury data suggested a 13-percent decrease in concussions on all types of plays. In addition to kicking from the 35, the coverage team can line up only five yards behind the kickoff line, minimizing a running start.
The desired outcome of increased safety has seemingly been achieved, but some will say the excitement has dissipated with so many touchbacks. However, TV ratings will refute any loss of interest and the records for offensive yardage have been rewritten every season since 2009. The latter would make sense even to fans with no interest in numbers. Well, they're starting at the 20 so often now, of course there are more yards to gain!
With expectations that scoring would decrease, something interesting has happened instead. The last three seasons, all under the new kickoff rule, are the three highest-scoring seasons in the Super Bowl era. The 2013 season's average of 23.4 points per game is the highest in any of the NFL's 94 seasons.
Has moving the kickoff five yards unintentionally sparked an offensive revolution? Let's examine the full impact of this rule change.
Kicking off from the 35-yard line is nothing new. The NFL did it from 1974 to 1993. There was such an offensive lull in the early '90s that the league actually moved the kickoff back to the 30-yard line in 1994 just to invigorate some excitement. The touchback rate had reached 26.5 percent in 1993, but instantly fell to 7.0 percent in the first season after the five-yard move. In 17 consecutive seasons (1994-2010) at least 80 percent of all kickoffs were returned. You could call this period the golden age of kick returns, highlighted by players such as Josh Cribbs, Desmond Howard, Dante Hall, Devin Hester, Brian Mitchell and Leon Washington.
But since 2011, things have changed drastically. The following table looks at the period differences in kickoffs by average distance, percentage that go out of bounds (OOB%) and the rates of touchbacks (TB%) and returns (RET%).
Data from NFL.com is only complete to back to 1992, but when we compare current numbers with the years 1992 and 1993 when kickoffs were at the 35, we see today's kickers are much better at driving the ball for touchbacks. We see it with the increased proficiency on field goals, but kickers are stronger and more accurate on kickoffs as well. Rarely does a kickoff go out of bounds these days -- John Kasay in Super Bowl XXXVIII aside -- but that was two or three times more likely to happen for most of 1992-2010.
After a period where 84.9 percent of all kickoffs were returned, just 51.5 percent have been returned since 2011. In the 2013 season the return rate fell to 48.0 percent -- likely the first time in NFL history fewer than half of all kickoffs were returned. Teams set a record with 1,309 touchbacks. There were 1,321 touchbacks in the 1994-98 seasons combined.
While it's clear the kickoff has not been eliminated from the game, a 39.3 percent decrease in returns is significant.
With seemingly every kickoff making it to the end zone these days, return specialists face some tough decisions. Do they take the ball out deep from their own end zone and risk not making it to the 20, or do they avoid the wrath of their coach and just kneel for the touchback? If they take it out, they better be confident it will be a good gain. Not surprisingly, the last three seasons have produced three of the highest kick return averages in NFL history:
|Highest Kick Return Average in NFL History|
This looks good, but is the average being inflated by those end-zone yards? We can look at the drive stats to help determine if these returns are actually beneficial for field position, which has naturally gotten worse across the league due to this rule change. I plotted the average field position (LOS/Dr) for all drives against the average field position following a kickoff (LOS/KO) for 1997-2013:
Overall starting field position is down about three yards and the gap continues to widen between overall field position and post-kickoff field position. With kickers getting more on the ball and the five-yard boost, there's roughly a seven-yard difference in where returners are catching the ball in 2011-13 relative to 1997-2010. Teams used to average 27.64 LOS/KO, but that has decreased to 22.22. That's also been very consistent the last three years with averages of 22.22 (2011), 22.15 (2012) and 22.29 (2013). I suppose that was bound to happen when nearly half the post-kickoff drives start at the 20.
Let's do a quick math estimation on the increase in yardage coming from the kickoff rule change. As I mentioned before, a new league record for offensive yards per game has been set every season since 2009. In 2010, the benchmark was 336.0. However, touchbacks started going up in 2006. With an average of roughly 830 more touchbacks per season in 2011-13 compared to 2006-10, that's about 26 more drives per team that start at the 20 instead of the previous post-kickoff average around the 27-yard line.
So teams had about 26 drives a season to gain seven more yards than usual starting in 2011. That comes out to 11.4 more yards per game. In 2011, the record for average total offense became 346.8 yards per game -- an increase of 10.8 yards per game. The 2013 season and its record number of touchbacks pushed the record up to 348.5 yards, or 12.5 more yards per game than in 2010.
Of course the league-wide pass ratio has continued to increase each season as well, and we know more points come out of the passing game, so that's a big factor in the record-setting numbers. But make no mistake about it; the change in field position from kickoffs has aided yardage records. Six of the eight 5,000-yard passing seasons have come since 2011.
Yards are easy to explain, but the scoring increase despite inferior field position is a little puzzling. Using the Drive Finder at Pro-Football-Reference, I collected data on drives starting at exactly the 20-yard line since 1999:
|Drive Stats: Starting At Own 20 (Source: Pro-Football-Reference)|
Wow, we went from about 100 80-yard touchdown drives to 250 per season since 2011. The percentages have also increased with offenses a little over one percentage point better at going 80 yards for a touchdown and three percentage points better at getting any type of scoring drive. You could say with the bigger sample size we're seeing more of the offense's "true" rate of success at going 80 yards for a touchdown. Teams certainly are getting more practice at it these days. Will these higher rates still exist when players like Peyton Manning and Drew Brees are retired and if the first round of the draft keeps adding players like Blaine Gabbert and Christian Ponder instead of the next wave of studs? That's been my response to the "offense is too easy today" viewpoint. Time will tell if this was a special era or if defenses are just outmatched.
Perhaps we should chalk some of the numbers up to various rule changes aiding the offenses along with some all-time great quarterbacks out there, but the kickoff rule is one change that would not seem to favor more scoring.
Speaking of scoring, how about kick return touchdowns? Right away after the kickoff was moved to the 30, return specialists set a league record with 16 kick return touchdowns in the 1994 season. The current record is 25 (2007) and the 2010 season was second with 23.
There have been 29 kick return touchdowns in the regular season since 2011. Last year's total of seven was the lowest since 1993 (four). Of course with nearly a 40 percent decrease in returnable kickoffs, this was to be expected. In terms of the percentage of returns that result in a touchdown, nothing has changed with a 0.73 touchdown percentage in 1994-10 and a 0.71 touchdown percentage in 2011-13. In the last two Super Bowls, Jacoby Jones (Baltimore) and Percy Harvin (Seattle) opened the second half with a kick return touchdown to extend to a commanding lead. It's still a part of the game and return specialists can still shine. They just get fewer opportunities.
Sticking with scoring, my hypothesis from 2011 was that the kickoff change could make it easier for one team to hit the opponent with a scoring run. Consider this feasible scenario:
That can snowball quickly. We know expected points increase with each yard gained, so starting in bad field position is a burden on even the best offenses. I've highlighted that many times with the postseason. But field position can be turned around by one good drive, so in my example, Team B could eventually turn the tables in their comeback attempt and do the same thing Team A did earlier in the game.
That's essentially what the Patriots did to the Broncos in last year's 24-point comeback. Denver's lead was built almost exclusively on takeaways and short fields -- an unsustainable strategy. Once the Patriots scored to start the second half, Denver was now the team consistently pinned deep and New England forced mistakes and took advantage of the better field position. Denver did the same thing in San Diego in 2012, flipping the turnover and field position battles in the second half to come back from a 24-0 deficit. The Chargers' second-half drives started at their own 15, 22, 15, 32, 14 and 20. Five of those drives started after a deep kickoff following a Denver touchdown. This type of comeback has become alarmingly common these days.
Since 2011, 16 teams have won a game after trailing by at least 18 points. That happened 16 times in the 2004-10 seasons combined.
From 2001-10, only one time did a team win after trailing by more than 21 points. Since 2011, it's happened five times, including a 28-point comeback by the Colts in the playoffs.
I'm not trying to declare this one kickoff rule is leading teams to string together scoring drives (many still of the long variety), but it's been incredible to watch the collapses the last three seasons. Yes, mistakes like turnovers are likely still the driving force for both scoring runs (the lead and then the opponent's comeback), but it never hurts to win the field position battle.
When Green Bay erased a 23-point deficit in Dallas last season, field position told much of the story. Green Bay started its first nine drives at exactly the 20. In the fourth quarter, the Packers were able to start a drive at the Dallas 22 and the game-winning drive at the 50 (following a Tony Romo interception). Green Bay finished the game with five consecutive touchdowns in the second half, a half in which Dallas started at its own 20 or worse on all five drives and scored 10 points.
With kick returns diminished, there's just not as much variance in field position anymore. Since 2011, the variance for LOS/KR is 1.79. It was 3.89 in 2008-10. Some teams used to be able to create a significant advantage with their return game. That's much harder when even the lesser kickers are capable of getting the ball to the end zone often enough.
The NFL's not in NBA territory yet when it comes to scoring runs, but it might get there. Scoring's always been the point of the game, but it now comes with an extra advantage when you have nearly a 50 percent chance of making sure the opponent's ensuing drive starts 80 yards away from the end zone.
After going all stat nerd over a rule change, I saved the stuff the NFL cared most about for last: the injuries. That was done on purpose, because frankly we do not have any new data to share on 2013 injuries for concussions (total and on kickoffs).
As always, NFL injury data is inconsistent and very unofficial. To the best of my knowledge, the league never did release numbers in 2011 about how many injuries (concussion or other) were suffered on kickoffs, so we never have really known if kickoffs were significantly more dangerous than scrimmage plays or how much improvement has been made with the rule change.
I posted numbers from Edgeworth Economics last season that showed 26 kickoff concussions in 2012 and 20 in 2011. That was a good improvement from 2010's total of 35, but there were still 265 total concussions in 2012 and 266 in 2011. We'll possibly get the 2013 update from Edgeworth Economics this summer, but these numbers almost never match the NFL's releases. This article says 190 concussions in 2011. This AP release has the following concussion totals: 252 (2011), 261 (2012) and 228 (2013).
Kickoff returns are not safer than they were before; they are just more infrequent compared to past seasons. Regardless of which injury numbers are right, the league must do its best to make sure the numbers stay down. But should the course of action be to further diminish the number of returnable kicks? It's not that touchbacks are injury-free plays, but the likelihood of a major collision is greatly decreased.
In March, the owners voted down a proposal to move the kickoff to the 40-yard line, which actually used to be the spot many decades ago. That would be overkill in today's game where kickers are already quite good at touchbacks. Moving it five more yards would likely result in at least 75 percent touchbacks and make a lot of return specialists expendable. A player like Trindon Holliday has almost no roster value at that point. Many players on the bubble maintain roster spots by impressing on special teams, but that's hard to do if there's nothing to hit or no one to block for. Denver's Terrell Davis first made a name for himself by delivering a big hit on a kickoff in the 1995 preseason. Is this the end of stories like that one?
The league should keep kickoffs at the 35, but if there's a change to consider, it would be making a touchback result in the drive starting at the 25. That would really give returners a lot to think about and likely would further decrease the number of returns. It also might spark some new strategies for when to punt. We already hate seeing teams punt inside the opponent's 40, but maybe a touchback at the 25 would lead to more fourth-down attempts.
Then again, we are talking about the decision making of NFL coaches. No one questions how safe that is. So safe, you wouldn't believe it.
11 comments, Last at 30 Nov 2016, 2:59pm by almasdar