Throughout the 2018 regular season, the Seattle Seahawks made a conscious effort to establish the threat of the running game in the minds of their opponents. In the face of record offensive production across the NFL — driven in large part by prolific passing offenses — head coach Pete Carroll doggedly maintained that sticking with running the ball gave the Seahawks the best chance to win. Though they attempted the fewest passes in the NFL, the Seahawks went 10-6 and earned a playoff berth.
But that reliance on the run may have been Seattle’s undoing in its 24-22 loss to the Dallas Cowboys in the NFC wild-card game. In the first half the Seahawks’ running backs rushed nine times for an anemic 2.1 yards per carry. Most of those runs came in a particular sequence: rush-rush-pass. All but three of Seattle’s first-half rushing attempts originated from the rush-rush-pass play sequence. And despite the lack of success using that pattern of plays against the Dallas defensive front, Seattle opened its first possession of the second half by calling it again. The result was a punt.
The notion of establishing the run is deeply ingrained in NFL culture. Coaches and play-callers laud the approach for its ability to keep a team “on schedule” and “ahead of the chains,” both of which are football shorthand for picking up enough yards on first and second down that you stand a good chance to extend a drive. True believers think that if you abandon the run too early, you make your team one-dimensional and forfeit an important edge in toughness. You’re no longer imposing your will on a defense, and this will manifest itself in worse results overall. But is this true? Does running help a team convert more first downs and extend drives? And does the order in which you call pass and run plays matter?
To answer these questions, I looked at every play called in the NFL regular season from 2009 to 20181 and compared the result of each of the possible permutations of run and pass play sequencing2 using expected points added and success rate.3 I calculated EPA and success rate for every first-down play; then I looked at every sequence that did not absorb into a first down and extended to second down and then third down, calculating the EPA and success rate for each call.
Leaguewide, rushing is the preferred play call on first down, after which passing takes over as the dominant play type, especially on third down.
Over the course of the 2018 season, there was no three-play sequence that Seattle favored more than rush-rush-pass. The Seahawks called rush-rush-pass 26 percent of the time, a rate 10 percentage points higher than league average. Yet despite the high frequency with which Carroll and offensive coordinator Brian Schottenheimer used the pattern, they were not successful with it. Just 41.2 percent of their rush-rush-pass sequences ended in success. Meanwhile, on three-play sequences where the Seahawks started with a pass and mixed in a run afterward, they were successful 88.9 percent of the time (pass-rush-rush), 71.4 percent of the time (pass-pass-rush) and 50 percent (pass-rush-pass) of the time.
These results hold generally across the league as well. Pass-rush-rush is the most successful three-play sequence, followed by pass-pass-rush and rush-pass-rush.
On first down, passing will net you at least 5 yards (enough to make the play a success) 47 percent of the time, while running the ball will get you the same result just 32.8 percent of the time, 14.2 percentage points less often. On second down, the gap closes to about a 7 percentage-point advantage for passing.
Play-calling patterns that end in a pass on third down have a negative expected value across the board. If we look at each sequence in terms of EPA per play, we see that the only positive EPA values on third down are on running plays. This makes sense: If you are passing on third down, it strongly implies that the first two plays in the sequence did not end well, and you likely have a third-and-long situation.
Meanwhile, the opposite outcome is true on first and second down. There are no positive EPA rushing nodes, and all passing plays return positive expected value.
This result is the exact opposite of what we would expect to find if establishing the run via play sequences like rush-rush-pass were winning strategies. Instead of making a team less predictable, establishing the run on first and second down creates a game state that is often quite predictable for the defense. The opposing team is expecting a pass on third down because the first two plays were unsuccessful.
Surprisingly, two of the top three teams in net yards per passing attempt in 2018, the Rams and the Chiefs, actually do have success with the rush-rush-pass play sequence.
Kansas City, the most dominant passing team in the league, was successful 53.3 percent of the time with rush-rush-pass. But the Chiefs ran the sequence just 15 times all season for a total share of 9 percent of all plays — 7 percentage points below league average — and they were mostly unsuccessful with the first two plays in the chain. When the Chiefs called back-to-back runs on first and second down, the second run was successful just 47.7 percent of the time. This suggests that the success of their third-down passes owes itself more to the strength of the Chiefs passing game and quarterback Patrick Mahomes than to the running plays that led up to them.
The story is similar in Los Angeles. Sixty percent of rush-rush-pass play sequences ended in success, and the Rams used the pattern at exactly the league-average frequency. Again, however, when the Rams called back-to-back runs to begin a sequence, the second run was successful just 46.1 percent of the time, leaving them 5.8 yards left to gain for a first-down conversion on average. The success the Rams enjoyed on third-down passing attempts appears to be independent of the rushing plays that preceded them.
While the precise order in which passes and runs are called may not matter so much — several combinations are roughly equivalent to one another according to success rate — some trends are clear. Passes are more effective when called on early downs, and runs are more effective on third down. Running on first down, while often a mistake, can be salvaged with a pass on second down. And if you’re going to rush on back-to-back plays to open a series, you should do so sparingly because it will leave your team in an obvious passing situation more often than not. Your passing attack — and QB especially — will need to be well above average to consistently convert in those high-leverage spots where all deception is gone and defenders can be confident that they know what’s coming.
Previewing the NFL divisional playoff round
Check out our latest NFL predictions.