Twitter's character limit leads to abbreviated statements that are often shorthand for a larger argument. These arguments aren't always well conveyed, especially on Twitter. If you want to understand the arguments and the evidence behind them, keep reading.
Here's a nerd-to-human translator.
-- Ben Baldwin, @benbbaldwin
"Running backs don't matter"
What the nerds say: running backs don't matter
What the nerds mean: the results of run plays are primarily determined by run blocking and defenders in the box, not who is carrying the ball. Running backs are interchangeable, and investing a lot of resources (in the draft or free agency) doesn't make sense.
- Eric Eager: Are NFL running backs easily replaceable: the story of the 2018 NFL season
- JJ Zachariason: Saquon Barkley May Be a Generational Talent, But He'll Still Be Overdrafted
- Lau Sze Yui (@903124S): Running backs don't matter! Overview of NFL running play analytics
- Ben Baldwin: Throwing to running backs: The latest NFL craze that doesn’t make any sense
- Big Data Bowl: 1st place solution The Zoo
Summary: the most convincing recent evidence we have is from the Big Data Bowl, where the winning entry found that the best prediction of the result of a running play -- given the positioning of the offense and defense at the time of handoff -- can be made by ignoring the identity of the running back. This means that in a predictive sense, the only channel through which running backs "matter" on run plays is their position and acceleration at the time of the handoff. But there isn't much evidence that that's something that's stable for players over time.
"Sacks/pressures are a quarterback stat"
What the nerds say: Sacks/pressures are a quarterback stat
What the nerds mean: Variation in sack rates and pressure rates across teams is primarily determined by quarterbacks through how long they hold the ball, not offensive lines. Do not use sack or pressure rates to measure offensive line play.
- Eric Eager: Quarterbacks in control: A PFF data study of who controls pressure rates
- Jason Lisk: What quarterback rate stats stay most consistent when a quarterback changes teams?
- Michael David Smith: Fun With Sacks, Part II
Summary: Eager's piece has the most detailed explanation, but here's a snippet: "Simple decision trees, which random forest models ensemble to make their predictions, always choose to split at the pressure rate for the quarterback first (and often second and third), as opposed to that for the offensive linemen (or each of individual offensive linemen when I tested this). Thus, at this point, it’s pretty safe to say that modeling of the play-by-play data at least does not refute the prior, simple, analyses that quarterbacks “own” their pressure rates more so than the rest of his offense does."
"You don't need to run to set up play action"
What the nerds say: You don't need to run to set up play action
What the nerds mean: At the ranges that NFL teams currently run the ball, there is no evidence that a run-heavy approach is needed for play action to be effective. Teams do not need to run the ball early in games to set up play action. It just works.
- Ben Baldwin: Rushing Success and Play-Action Passing
- Ben Baldwin: Play-Action Passing and Game Conditions
- Josh Hermsmeyer: Can NFL Coaches Overuse Play-Action? They Haven’t Yet.
"Defense doesn't matter"
What the nerds say: Defense doesn't matter
What the nerds mean: Measured defensive performance in the past is only weakly related to measured defensive performance in the future. Predictions of future team performance should weight offense higher than defense.
- Josh Hermsmeyer: The Patriots’ Defense Is Good. That Doesn’t Mean It’s Going To Stay Good.
- Ben Baldwin: Does defense matter? With Russell Wilson facing the 49ers, we’re about to find out
- Jim Armstrong: Turnovers and the Unpredictability of Defense
Summary: From Hermsmeyer, "There’s a lot we don’t know about teams early in the season, but after nine or 10 games, we like to think that we have a decent idea about how each unit will perform in a given game, especially late in the season with the playoff picture in focus. This turns out to be partially true — for the offense, anyway. Our ability to predict a team’s offensive performance in an upcoming game does improve as the year goes on, peaking around Game 11. But, surprisingly, this isn’t true for the defense. We know roughly as much about a team’s upcoming defensive performance after one game of results as we do after 12 or 13."
"Coverage > pass rush"
What the nerds say: coverage > pass rush
What the nerds mean: What happens on the back end is more predictive of who wins the game than the battle between pass rush and pass protection.
- Eric Eager and George Chahrouri: Coverage vs. Pass Rush
- Eric Eager: Coverage vs. Pass Rush Revisited
Summary: from Eager and Chahrouri, "The correlation between team-level coverage grades and EPA allowed per pass play during that season is roughly -0.69. EPA correlates with pass rush at a rate of roughly -0.23 [...] PFF grades in coverage explain more about what happens in the passing game in a given season than pass-rush grades do [...] Coverage grades both explain and predict defensive success better than pass rush, but they come at the expense of year-to-year stability at both the player and team level. "
Collection of other seminal pieces
Description of various measures // approaches
- Ronald Yurko: An Introduction To Expected Points (EPA and why the nerds use it)
- Ronald Yurko, Samuel Ventura, Maksim Horowitz: nflWAR: A Reproducible Method for Offensive Player Evaluation in Football (detailed description of nflscrapR EPA model)
- Bill Barnwell: Receiving Plus/Minus, Part I (first to adjust completion percentage for depth of target as deeper passes are less likely to be caught than short passes)
- Josh Hermsmeyer: The NFL Is Drafting Quarterbacks All Wrong (introduction of CPOE)
- Seth Walder: Pass blocking matters more than pass rushing, and we can prove it (Pass Block Win Rate)
- Timo Riske: Investigating pass protection with survival analysis
- Timo Riske: Using Survival curves to investigate trench warfare in the NFC Championship Game
- PFF: Introduction of WAR
- Brian Burke: 4th Down Study (derivation of 4th down decision-making)
- Brian Burke: How Coaches Think: Run Success Rate ("[Coaches are] looking down at the sport from a 10-foot ladder when they should also be looking at it from the 10,000-foot level")
- Derrick Yam and Michael Lopez: Quantifying the causal effects of conservative fourth down decision making in the National Football League (and see follow-up from Lopez here)
- Benjamin Morris: When To Go For 2, For Real