Entering Week 4 the Dallas Cowboys led the NFL in third-down conversion percentage, as the Dak Prescott-led offense has converted 52.5 percent of its third downs. On Sunday in San Francisco, in the come-from-behind 24-17 win (full coverage here), the Cowboys' 6-of-14 ledger on third down was certainly one of the reasons they beat the 49ers and, overall, their conversion rate is a big reason they're 3-1 as the season's first quarter concludes.
But how important is it to convert on third down? And are there any factors that go into being a good converting team on third down? We go deep into that today.
I sampled the last five seasons in the NFL, breaking down the Cowboys’ conversion rate, the conversion rates of the league’s playoff teams and the conversion rate of the league’s non-playoff teams. Those conversion rates — the five-year average — is below:
Dallas Cowboys: 40.02 percent (2014 playoff team: 47.3 percent; other four non-playoff seasons: 38.2 percent)
Playoff teams: 40.66 percent
Non-Playoff teams: 34.6 percent
So there is a significant difference in the third down conversion rate between playoff teams and non-playoff teams in the past five years. It’s a six percent difference. For the Cowboys the difference is nearly nine percent between its playoff season and its four non-playoff seasons in that span. But why is there no difference between the Cowboys’ five-year average and the average of those playoff teams? Especially since the Cowboys have only been to the playoffs once in that five-year span?
Curious, most curious. That led me to dig deeper.
Now you can find all sorts of data out there when it comes to pro football these days. My goal, after learning the above, was to determine if there was any other data that might be influencing why the Cowboys’ third-down rate was on par with other playoff teams, whether or not it made the playoffs.
Does a team’s average of total plays per game make a difference?
Playoff teams averaged anywhere from two to three additional plays per game than non-playoff teams. Oddly, the Cowboys held true in that regard as well. Their plays per game in their one playoff season in the sample — 2014 — was about two more than the average of the other four seasons. Now, two to three additional plays in a game doesn’t sound like much. But take the average — let’s say 2.5 per game — and multiply it over 16 games and you get 40 plays. Now that has the potential to make a difference.
So I think we can say that plays a role, but is not an overriding factor. By the way the Cowboys had 72 total plays against San Francisco on Sunday.
What about yards per play?
Playoff teams average about 5.62 yards per game in the five-year sample. The Cowboys, oddly enough, averaged slightly better — 5.76 yards per play. Non-playoff teams were in the 5.0 to 5.2-yard range. So, on average, most NFL teams are dealing with manageable downs and distances consistently. That doesn’t seem like something that would influence third down conversion rates that much. But if you're interested the Cowboys were 5.9 yards per play on Sunday.
What about the number of third downs a team faces per game?
There is less than a one play difference between playoff teams and non-playoff teams, including the Cowboys. There is no real influence there based on the data.
What about first downs per play?
Now we’re getting deep into data. Playoff teams in the past five years averaged .322 first downs per play. The Cowboys during that same span averaged .327 first downs per play. While their rate (.339) was on the high end of the average during their playoff season, the difference with the average is negligible.
What about the types of plays a team runs to get a first down?
So here’s something that made a difference. While the spread between run plays and pass plays to get a first down was relatively static over five seasons, the number of running plays to get a first down did make a difference. Playoff teams in the past five teams averaged 104.6 running plays for a first down. That runs close to what the Cowboys did in their one playoff season in 2014 — 106 running plays for a first down. In the other four non-playoff seasons the Cowboys averaged 85.2 run plays for a first down.
What about non-playoff teams in 2015? Well that average was 87.7. And in 2014? 87.4. And it ran that way for the other three years in the sample.
So what we have here is our one true distinction. Playoff teams in the past five years — including the Cowboys — tend to convert more first downs running the football than non-playoff teams. In fact, by an average of about 15 plays per season. Now, I can’t accurately determine how many times a team ran the ball on third down in the sample, but this difference tells me that these playoff teams are probably facing shorter downs and distances on third down and feature offensive lines good enough to get the job done in short-yardage situations.
You can draw a line from some of the other data we delivered here. Specifically, the small difference between yards per play. The more yards per play a team averages, the better their chances of facing shorter downs and distances on critical downs, which is what coaches tell us all the time and plays into the assumption above.
So let's look at the Cowboys on Sunday. They were 6-of-14 on third down, right? Well the Cowboys were 3-of-10 on third down while throwing the football. They were 3-of-3 running the ball, including two strong runs by Ezekiel Elliott. So the number of first downs run and pass on third down on Sunday was balanced.
The Cowboys have two kids in the backfield who are getting the job done, and now owner Jerry Jones is able to utter the word "playoffs'' when you try to get him to utter the words "QB controversy.''
“We know we that we dream of having that kind of dilemma,” Jones said. “I know that everyone associated with it prays that we have that kind of dilemma. I would love to have that problem. But the way I look at it is that we are working toward getting pretty sound at that position. That is a good place to be as you look at the next 12 games in the NFL and playoffs is to be really sound at that position. I think we aren’t out over our skis a little bit to think that way.”
"Out over our skis!''
You know, sometimes you mine data and you find exactly what you’re looking for. Sometimes you don’t. I went into this thinking that I was doing to find some sort of unknown silver bullet that would be the answer to converting on third down. Turns out the reason may be the reason the Cowboys are having success with the kids in the backfield, especially having drafted Ezekiel Elliott at No. 4 overall.
Teams that convert third downs at a higher rate tend to make first downs by run at a higher rate and tend to make the playoffs.
So yes, teams are throwing the ball at record rates. And Prescott has been Romo-like at that in many ways. But success in the NFL still means running the ball, something the Cowboys seem committed to as Elliott put up his second straight 100 yards game and the Cowboys hung 194 yards rushing on the 49ers. ... and therefore "3rd-and-Won.''