Big plays and turnovers; that’s how games are won in the NFL. Are we incorporating these two separate ideas properly into how we see a teams’ success? There are formulas that try to marry the two together, but they speak of turnovers in the traditional sense by using only fumbles and interceptions.
Is there a better way? I recently asked Twitter this very question in a thread of polls.
Are missed field goals turnovers?— Michael Kist (@MichaelKistNFL) August 7, 2018
To my delight, the consensus agreed that the old method of tallying only interceptions and lost fumbles didn’t tell the whole story. That gave me the motivation needed to create a new formula to broaden the scope while zeroing in on stronger win correlations. This formula also accounts for the all-important explosive play, so let’s take on these different aspects of the formula one by one, starting with chunk yards.
Explosive plays are what every offense is trying to create. Explosive plays are what every defense is trying to prevent. These are obvious statements. But what impact does that ultimately have on a teams’ success? For this metric, all plays of 20+ yards allowed by the defense are subtracted by all plays of 20+ gained by the offense. In 2017, the top 11 teams in EM had winning records. This is what the last 5 years have produced for teams with a positive EM:
- 29 of 40 division winners (8 of 8 last year)
- 42 of 60 playoff teams (11 of 12 last year)
- 9 of 10 Conference Champions
- 4 of 5 Super Bowl Champions
No team had a bigger swing in big plays last year than the Super Bowl Champion Philadelphia Eagles. They went from a 31st worst -25 EM to t-7th in the league with a +13. The variance of +38 led the league by a lot. The San Francisco 49ers saw improvements on both sides of the ball under new head coach Kyle Shanahan, boosting them to a +31 EM variance. The shift was only good enough to push the 49ers to the middle of the pack after their disastrous, league worst -35 EM in 2016. Next in line were the Minnesota Vikings at a +18 swing on the back of stable play from quarterback Case Keenum and a historic performance by the defense (until, you know...).
“Cashing in on splash-play opportunities – I don’t think enough is written and said about that. A lot of times we talk about minutiae and interesting things and statistical things and so forth, but I think being a group that’s opportunistic and being capable of cashing in on opportunities when presented needs to define us...” – Mike Tomlin, Pittsburgh Steelers Head Coach
The Eagles significantly improved on both sides of the ball and it led to substantially more wins. If you’re worried about a regression from the Eagles, the additions of Mike Wallace and Dallas Goedert, combined with the potential emergence of second-year deep threat Shelton Gibson should ease those concerns. The secondary has a batch of young corners ready to take the next step in their development. If they do, they will continue to reduce the number of big plays allowed.
As I’ve noted before, turnover margins have forever been heralded as the difference between wins and losses. During pre-game shows, chances are high you’ll see “win the turnover battle” in the “Keys to the Game” graphic.
The link between being a + in the turnover margin and winning games is undeniable. A study by Football Perspective found winning percentages based on winning the turnover battle to be remarkably static.
“Last year, teams that won the turnover battle won 78% of their games. And from 2007 to 2016, teams that won the turnover battle won 78% of their games. In the decade of the ’70s, when turnover rates were much higher, teams that won the turnover battle won 78% of their games. From 1950 to 2016, the average winning percentage of teams that won the turnover battle was 78%, too.”
Former Baltimore Ravens coach Brian Billick created what he called “toxic differential” during his time in the league. That formula accounts for Explosive Margin (EM) and Turnover Margin, but the issue I have is the how turnovers are represented, which I feel have long been misrepresented and need a face-lift.
For a point of reference, from 2016-2017, the Eagles won or lost 77% of their games based on the + or – in the turnover column. But what if we could form a stronger link with winning? What if we are looking at turnovers the wrong way? There are two aspects of the game that, to me, should be counted as turnovers.
MISSED FIELD GOALS
A team lines up at the 30-yard line to set up for a 48-yard field goal. The kick flies wide right and the opposing team takes over at the spot of the hold. The score doesn’t change. In terms of Expected Points Added (EPA), a field goal adds 3 points, obviously. From this distance, a missed field goal subtracts 1.47 points. The difference the miss creates equals 4.47 points. That’s a significant swing, no?
In 2015, the Eagles played the New York Jets. In Eagles territory with 2nd & 10 from the 30-yard line, Ryan Fitzpatrick threw an interception to Jordan Hicks that was downed immediately. The play ended on the Eagles 32-yard line, giving them only 6 less yards in field position than the missed field goal. The EPA for the Jets before the play was 3.03. The EPA after the play was -1.07. That’s a swing of 4.1 points, .37 less of a swing than the missed field goal.
There are other factors in play with EPA but the point is this, if it’s that close of an impact on points, why are they not thrown in the same bucket? The other team takes possession of the ball, significant points were swung in another teams’ favor, yet it’s not properly reflected in the box score or the pre-game rhetoric.
Why not punts? There’s a change in possession on those as well? Sure, but the impact on EPA is negligible. We’re talking fractions of points swinging as opposed to chunks. Perhaps when we gain a better understanding of Game Winning Chance, the formula Edj Analytics uses, we can take a deeper look at how punts inside enemy territory impact games. Until then, we’ll just call coaches who consistently take that route cowards.
FAILED FOURTH DOWNS
Using the example of EPA from the enemies 30-yard line again, it’s my belief that failed fourth down should be treated as turnovers. After all, they’re literally called a “turnover on downs”, right?
In the past 5 years, there have been 37 attempted fourth downs from the opposing 30-yard line. On conversions the EPA swung an average of +3.07 points added, while failures swung an average of 2.74 points lost. That’s an average swing that ranges 5.81 points, which is significant.
Not all fourth downs are created equal, but their impact on the game can’t be underestimated. You’re Eagles fans; you understand these things.
REARRANGING THE “ATOM”
Considering the impact on the game of traditional turnovers (fumbles/interceptions) against the impact of missed field goals and failed fourth downs, I’ve created a new formula. Adjusted Turnover Margin, or ATOM, aims to show a stronger correlation to wins and losses.
I used the 2016-2017 Eagles seasons as my guinea pig. Again, turnover margins have stayed stable at 78% correlation over the years, but this fluctuated from 83% in 2016 to 71% in 2017 for an average of 77%, only one percent off the lifetime average.
The admittedly small sample size for ATOM shows an even stronger correlation. It’s even more encouraging that the numbers didn’t fluctuate to hard from one year to the next, going from 86% to 87% and ultimately averaging out at 86%. My hope is this holds up over a much larger data set, but it’s an encouraging start.
PLANTING THE “MEAT” FLAG
There are two ways I’m looking at Margin of Explosive Adjusted Turnover aka MEAT (thanks @BenjaminSolak). The first way is to bring the two numbers together to form one number.
Here are the rules for the formula.
- Explosive Margin (EM): Plays of 20+ yards created by the offense, minus explosive plays allowed by the defense.
- Adjusted Turnover Margin (ATOM): Interceptions + fumbles + missed field goals + failed fourth downs vs. your opponent
- Margin of Explosive Adjusted Turnover: EM + ATOM = MEAT
It’s simple, did your team plant their MEAT or is their MEAT garden bare? Applying this formula to the 2016-2017 Eagles showed a correlation on individual games that fit right between ATOM and the traditional turnover margin. In 2016, a + or – MEAT had a hit rate of 85%, in 2017 it dropped slightly to 80%, and overall it averaged out to 82%.
The other way to utilize this is treat the two formulas as boxes that need to be checked. In other words, is your MEAT double stacked? The strongest correlation to wins and losses came when the Eagles checked boxes on the positive or negative side in both EM and ATOM. In the last two years they had this happen 10 times and the outcomes were determined by the + or – all 10 times.
I’d be foolish to say there are any definitive takeaways about which margin or margins are best from the data I’ve cited; the sample size just isn’t large enough. However, I do believe the impact of explosive plays are vastly underrated and the logic I’ve presented regarding the definition of a turnover is sound, regardless of future findings of correlation/causation.
I’ll be taking my pickaxe with me to the data mines to present a larger picture and will also be tracking these metrics throughout the 2018 NFL season. I’m confident ATOM will continue to show a stronger correlation to winning than traditional turnover margins and with more research I’m hoping I can plant my MEAT flag firmly.