What if I told you there’s a stat that accurately correlates with Dak Prescott’s QB record in 33 out of 36 games?
The game of football is predicated on “moving the sticks” to achieve a new set of downs. And Dak Prescott’s ability or inability to move the sticks is a key driver of the Cowboys’ W/L record.
We measure QBs by all sorts of real and made-up stats, but there is no readily available stat that measures a QB’s ability to move the sticks.
The simplest way to do that is to add up a QB’s passing and rushing first downs and divide them by his number of dropbacks and runs. The resulting QB first-down percentage (or 1D%) may not be perfect, but it removes some of the inconsistencies that plague some other stats, i.e. it does not reward a QB for completing a 15-yard pass on 3rd-and-16, nor does it reward the QB for throwing a screen pass the RB takes 80 yards for a TD. On the downside, because it’s about first downs, it tends to undervalue QBs from big-play offenses, and tends to reward QBs who are able to sustain long methodical drives.
Let’s take Dak Prescott’s rookie season to illustrate the 1D% stat. Per Pro-Football-Reference.com, Prescott had 186 passing first downs on 483 dropbacks (458 pass attempts + 25 sacks), and 21 rushing first downs on 44 runs (excluding kneel-downs). In total, that’s 207 first downs on 527 plays, a 39.3 QB 1st down percentage. In 2016, that was the second-best value in the league, second only to Matt Ryan.
When we originally looked at 1st-down percentage in detail in a post at the start of the 2017 season, we had just 17 games worth of data to work with for Dak Prescott. Today we have 36 games worth of data, and we can see a stunning correlation:
- When Dak Prescott has a 1st-down percentage of 30% or higher, the Cowboys are 23-2.
- When Dak Prescott has a 1st-down percentage below 30%, the Cowboys are 1-10.
Here’s a visual summary of Prescott’s 36 NFL games to date; wins are marked in green, losses in yellow, the red line marks the 30% first-down percentage threshold.
The three games that are outliers:
- Game 20 (Week 4, 2017): Prescott puts up a 1D% of 34.1% in the loss against the Rams.
- Game 21 (Week 5, 2017): Cowboys lose to the Packers despite a 43.9% 1D% by Prescott.
- Game 28 (Week 13, 2017): Cowboys win despite a subpar (28.6%) performance by Prescott against the Redskins.
In every other game, the first-down percentage accurately correlated with the outcome of the game.
And that has carried over to 2018, where the 30% threshold was accurate in all four games:
|Week||Opp||W/L||Pass Att||Sacks||Pass 1D||Runs||Run 1D||Tot Plays||TOT 1D||1D%|
Admittedly, that Giants game is exactly on the 30% mark and could have gone either way, but the Cowboys got lucky in that Eli Manning proved even more inept at moving the sticks with a 24.5% first-down percentage.
A breakdown of Dak Prescott’s 1D% numbers through the first four games might be even more instructive. The following table lists Prescott’s numbers by target:
|Target||Plays||1st downs||1st down %|
|Incomplete (no clear target)||2||0||0%|
The tiering here echoes something we saw last week in a post on Expected Points Added (which is no surprise, given that both EPA and 1D% place a premium on first downs, unlike more blurry metrics like success rate, YPA, or passer rating).
Cole Beasley, Tavon Austin, and Deonte Thompson are the receivers who move the sticks at an above average rate, Terrance Williams, Geoff Swaim and Allen Hurns are around average, everybody else is below average (even if we run into sample size issues with the remaining pass targets).
The data here covers all four games, so even if a player like Ezekiel Elliott had a great game as a receiver against the Lions, that doesn’t remove the subpar performance he had as a receiver in the first three games.
Obviously, the hope here is that the Lions game is more indicative of the future performance of the offense than the first three games are. And if we isolate the performance against the Lions, the future looks bright for the Cowboys’ receiving corps. Here are the receivers who were targeted more than once in the Lions game - and keep in mind that the Lions were the No. 1 pass defense heading into the game against Dallas.
|Target||Plays||1st downs||1st down %|
The Cowboys finally found a way to use Elliott much more effectively in the passing game, Beasley was his usual effective self, Swaim and Hurns were also effective for a change, and only rookie Michael Gallup didn’t have good numbers. But overall, that’s a promising performance from this group of receivers, even if we had to wait until the fourth game to see it.
At its core, football is about gaining at least 10 yards in three tries, and 1D% gives you a good idea of how successful a QB (and by extension the entire offense) is at at achieving a new set of downs.
The Houston Texans have allowed opposing QBs a 1st-down percentage of 38.5% over the first four games of the season, and those opposing QBs included two pocket statues in Tom Brady and Eli Manning. If the Texans allow Prescott a 38.5% first-down percentage, the stats suggest the Cowboys should have a winning record after Sunday.