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Pass Identities Through Seven Weeks

I’ve published the Game Scripts data from every game this year at the 2014 Game Scripts page, available here. What would it look like if we plotted Game Script score (on the X-Axis) against Pass Ratio (on the Y-Axis) for every game this year? Something like this:

game scripts
As you move from a more negative Game Script to a more positive one, the expected Pass Ratio decreases. But the relationship is not purely linear: in extreme cases, the Pass Ratios tend to move a bit more towards league average, and I think that trend is probably even stronger than it might appear on this graph. In any event, you can derive a best-fit polynomial equation from that data, which could give us an expected Pass Ratio.

Luck's Colts have been very pass-heavy in 2014

Luck’s Colts have been very pass-heavy in 2014

For example, with a Game Script of +3.0, teams should be expected to pass on 56.3% of all plays. But in the Eagles/49ers game, Philadelphia passed on 78.6% of all plays. At the time, I thought it was an oddly pass-happy performance, as it turns out, it was the most pass-heavy game of the year, with a pass rate 22.3% higher than expectation.

If we perform that calculation for every game this year, we can derive season grades. Let’s look at the Colts line in the table below. In 7 games this year, Indianapolis has an average Game Script of +7.9, which happens to be the highest in the NFL (the table is fully sortable). Based on how each game has unfolded, Indianapolis would be expected to pass on just 52.7% of all plays if it was an average team; however, the Colts have passed on 59.4% of all plays. That means the Colts have passed 6.7% above expectation, the second highest rate in the NFL this year. The table below lists that data for each team through week 7:

RkTeamGAvg GSExpActDiff
  • On the legs of DeMarco Murray, the Cowboys have been very run-heavy this year. But Dallas hasn’t even been the most run-heavy team in Texas; that honor belongs to Arian Foster and the Houston Texans.
  • Dallas, despite the gaudy 6-1 record, is just barely above average when it comes to Game Script. A -17.5 in week 1 is still skewing things for the Cowboys, and the -5.6 posted in the comeback win against the Rams two weeks later doesn’t help things much, either.
  • Both New York teams are among the five most run-heavy teams in the NFL. The Giants are a bit tougher to understand: New York has invested significantly in the passing game, but is focused on being a run-heavy team. Cleveland checks in as the 3rd most run-heavy team in the NFL so far this year, which jives with what I’ve seen watching the games.

We can also run the same numbers but look at the defenses To the surprise of none of our regular readers, the Jets are the defense that teams are least likely to run against (and, conversely, most likely to throw against). Opponents against the Jets have an average Game Script of +5.4; that would make you think they would throw on only 54.8% of all pass plays, but in fact, Jets opponents have passed on 61.6% of all plays. Teams pass 6.9% more often than they “should” if New York was equally strong against both the run and the pass. Alas, we know that is not the case.

RkTeamGAvg GSExpActDiff

On the other hand, teams really like running against Green Bay, St. Louis, and Oakland. The Raiders are not only a team that tends to have negative Game Scripts, but Oakland’s run defense is really bad, too. That’s a recipe for roughly a zillion carries for opposing backs. Oakland has allowed 217 opposing rush attempts this year, the most of any team through six games since 2010.

What stands out to you in these tables? Leave your thoughts in the comments.

  • Horse

    “On the other hand, teams really like running against Green Bay”
    Here’s what’s missing. Green Bay is #1 for Passer Rating Against. Of course teams will try to run more. Then, the first couple games run yardage given up was gigantic. It was a brand new defense. Then, decisions were made in some games against passing teams to max D against the pass, which takes resources away from run stop. None of your stats can tell you this.

    • Horse

      Clunky response system wouldn’t let me edit, so here’s the whole thing.
      “On the other hand, teams really like running against Green Bay”
      Here’s what’s missing. Green Bay is #1 for Passer Rating Against. Of course teams will try to run more. The first couple games run yardage given up was gigantic. It was a brand new defense. Then, decisions were made in some games against passing teams to max D against the pass, which takes resources away from run stop. None of your stats can tell you this. And you aren’t accounting for the non-correlation between run yardage and winning. But the scatter plots look cool.

      • Chase Stuart

        I am glad you agree with me that teams choose to run against Green Bay! Thanks for the comment.

        • Richie

          Why do people get so butthurt over statistical facts? There are no assumptions drawn here. This is mainly just a processing of factual information. It’s not an attack on Green Bay’s defense. Just showing that teams are choosing to run against them more often than expected.

          • It never ceases to amaze me how well people can turn things into insults when they are engaging in motivated reasoning.

            • RustyHilgerReborn

              Hey, maybe that guy is the Packers defensive line or linebackers coach in real life, therefore, the sentence he objects to could be taken as a jab at his professional accumen!

  • Curious: Are you suggesting scrapping the old z-score method in favor of this polynomial model? Sounds like you are, but wanted to confirm since I calculate these things myself — for entertainment purposes only, of course — immediately upon your publishing of the previous week’s game scripts & P/R ratios.

    • Chase Stuart

      Not necessarily – I just thought it would be fun to at things this way for a change, plus it might me more intuitive for some. Honestly, I’d probably look to people like you in deciding which method is better (or Neil’s method on 538). Any thoughts?

    • Ajit

      I would think the best thing to do is put it through some kind of filter and then run a simple regression.

  • RustyHilgerReborn

    Interesting stuff. Here in Lionsland, fans are complaining the offense is too conservative based on the fact Stafford is attempting far fewer passes (which I think is actually a good thing). But based on this, it looks like they’ve still been as pass happy as ever relative to their Gamescript.

  • Richie

    FYI – The “Diff” column in both tables is not sorting the negative numbers properly.

  • Joel W

    Things that stand out:

    1) Teams perceive New England’s run defense as significantly inferior to their run defense. Should be an interesting game with Chicago this weekend given how much Chicago likes to pass. Also, Cleveland seems like it might run 50 times against Oakland.

    2) I don’t know who made the decisions in Indy, but it seems like they’ve finally realized their strengths on offense. Green Bay still doesn’t seem to realize that its quarterback is the best in the league and its running game is mediocre.