The Dallas Cowboys are trying to do something this January that hasn't yet been accomplished in NFL history. Nobody has made it to the Super Bowl -- let alone won the big game -- with a rookie quarterback under center. After 50 Super Bowls, we obviously have seen 100 starting quarterbacks, and while there have been players who were nearly rookies (like Tom Brady in 2001), no passer has finished his debut season in the NFL taking snaps on the game's biggest stage.
If I were a Cowboys fan, I'd probably hear that and be both worried and hopeful. Hey, 50 years of history is a long time and a pretty good sample size, and there have been a lot of fantastic quarterbacks to come up short without one future Hall of Famer even eking his way through. I'd also probably be suggesting Dak Prescott isn't your typical rookie quarterback, with the phenom's superior performance making him more like a third- or fourth-year star than a mere pro freshman.
Both those sentiments are fair. To figure out why Prescott's reign would be unprecedented, we've got to take a look at what has happened during the Super Bowl era to see why rookie quarterbacks are 0-for-50. Let's ask and answer a few questions and get back to Prescott afterward.
Is it weird or surprising that we haven't seen a rookie quarterback in the Super Bowl by now?
Actually, yeah. It is.
I went through every season since the AFL-NFL merger of 1970, which leaves out the first four Super Bowls, although they also don't have any rookie quarterbacks. I picked out all the quarterbacks who started at least seven games (so a minimum of half the season going back to the 14-game slate) and threw at least 105 passes (for an average of 15 passes per game) and split them all up by the years of professional experience they had under their belt at the beginning of the campaign. So Prescott is a rookie, while Marcus Mariota has one professional season under his belt.
For every year of players with a given level of experience, I figured out how many quarterback seasons it took to typically get a passer to the Super Bowl. There have been 152 qualifying second-year seasons since 1970 -- that would be someone like Mariota this season -- and six of those guys have made it to the Super Bowl, most recently Russell Wilson in 2013. That's a rate of just under 4 percent, or one Super Bowl appearance for every 25.3 seasons.
Most every other experience level is between 10 and 20, with a couple of odd exceptions related to the relatively small samples. The numbers get smaller as players get into the teens of their careers, owing to selection bias: The quarterbacks who are playing in their mid-to-late 30s are generally extremely good and more likely to make a Super Bowl than a typical rookie.
Setting the cutoff for inclusion to seven starts eliminates a lot of hopeless rookies who are only in the lineup because the starter is injured (even if that's also how Prescott got here). But that still leaves us with 98 qualifying seasons that have turned into zero Super Bowl appearances. That's remarkable, and even if we assume rookies are all over the map in terms of performance, the difference between rookies and second-year players isn't that dramatic.
A very conservative estimate would suggest that one rookie season in 30 should turn into a Super Bowl appearance, which "should" have yielded three Super Bowl starts by now. Yet, if Prescott comes up short, we'll be looking at our 99th consecutive rookie campaign without a Super Bowl berth. Kinda crazy, right?
Split another way, 22 rookies have thrown 15 or more passes in a playoff game, most recently Connor Cook, who was overmatched during an ugly loss to the Texans in the wild-card round. Those starters, likewise, are 0-for-22 in Super Bowl trips. At other experience levels, usually between five and 10 players make the playoffs for every Super Bowl trip; second-year starters, for example, have made six Super Bowl runs in 48 tries, an average of eight per trip to the big dance.
We're not "due" for a rookie Super Bowl run -- that's the gambler's fallacy -- but it's a surprise we haven't had at least a couple by now.
Is it because rookies play worse in the postseason? Do they choke? They must choke, right?
Well, sort of.
Everybody is worse in the postseason than they were during the regular season, thanks to the cold weather and the likelihood of facing superior defenses. There are two sub-questions to keep in mind. One is whether rookie quarterbacks are worse than typical passers in the regular season, and the other is whether they drop off further in the playoffs than their more experienced brethren.
The answer to both is yes. To get a general gauge of quality, I used the pro-football-reference.com stat known as adjusted yards per attempt (AY/A), which is yards per attempt but with two other numbers included: passing touchdowns, which count for 20 yards, and interceptions, which count for minus-45 yards. This season's starting quarterbacks ranged from 10.1 AY/A (Matt Ryan) to 4.3 AY/A (Jared Goff).
Rookie quarterbacks, even the ones who qualify under the seven-start and 105-attempt rule, are significantly worse during the regular season than passers at any other experience level. With more than 32,000 pass attempts, rookies have averaged just under 5.5 AY/A when everybody else is above 6 adjusted yards per attempt. They're also the only group that throws more interceptions than touchdowns, as their collective interception rate is 3.9 percent.
We're not adjusting for era, so our playoff group of rookies should probably be better than we might think, given that most of the playoff appearances have come over the past 20 years as quarterback stats have risen. Given that we're also eliminating the truly dreadful rookie quarterbacks who weren't able to make it to the postseason, there's also reason to think rookies might actually be an exception to the playoff rule.
That's all wrong.
Rookies have been an absolute mess in the playoffs. Their adjusted yards per attempt falls to a borderline-unplayable 4.3, and they throw interceptions on 5.4 percent of their pass attempts. That's like Goff if the first overall pick threw four more picks on his 205 pass attempts this season. When rookie passers are collectively performing like Goff in the postseason, they're not doing very well.
Relatively, rookies are seeing their postseason AY/A decline by 21 percent and their interception rate skyrocket by 40.2 percent. I mentioned how everybody seems to get worse in the postseason regardless of age, but those changes dwarf the competition. I've put the comparisons together for quarterbacks through their first 10 seasons in the league, and nobody drops off as far as rookies, even though rookies are starting from the worst regular-season baseline:
Rookie quarterbacks also have the worst record in the playoffs, although it's not by quite as significant of a margin. Rookies throwing 15 passes or more (as the starter or in reserve) are 11-21 (.344) in the postseason after Cook's loss last week. That's the lowest rate among players of any experience level, but it's not all that far off from third-year quarterbacks, who are 37-57 (.394), or eighth-year passers, who are 26-42 (.382). If Prescott makes it to the Super Bowl, rookies would be in a dead heat with those frauds who waited eight years to reveal they couldn't handle the pressure of the postseason.
What about the superstar rookies?
Maybe by comparing him to all rookies we're not creating an appropriate context for Prescott. Using pro-football-reference.com's index statistics to scale and account for era, Prescott's AY/A translates to a 123 AY/A+, which is the sixth-best rate since the merger under the aforementioned seven-start, 105-pass criteria. Let's look at the guys in his ballpark who made the playoffs and see how they did after the regular season was over.
Pat Haden (1976 Rams, 134 AY/A+) just qualifies for this list, with exactly seven starts and 105 passes to his name. He didn't do much in the playoffs, though. Los Angeles won its divisional round game 14-12 over Dallas, but Haden was 10-of-21 for 152 yards with three picks before going 9-of-22 for 161 yards with two more interceptions in a conference championship loss to the mighty Vikings pass defense.
Ben Roethlisberger (2004 Steelers, 126 AY/A+) took over for Tommy Maddox and never looked back. His playoff run was a mixed bag. Roethlisberger led the Steelers back in the fourth quarter to tie the wild-card game with the Jets at 17-17, and also led a 14-play, 72-yard drive to set up a Jeff Reed chip shot for the win. He then threw three picks and fumbled once the following week as part of a 41-27 loss to the eventual Super Bowl-winning Patriots.
Robert Griffin (2012 Washington, 123 AY/A+) was a tragic case. He started off red-hot against a dominant Seahawks pass defense, going 6-of-9 for 68 yards with two passing touchdowns on the first two drives of the game, only to aggravate a knee injury attempting to make a throw on the run. Griffin was ineffective the rest of the game before suffering a more serious knee injury later, and he hasn't been the same player since.
Dan Marino (1983 Dolphins, 123 AY/A+) took over the starting job for good in Week 5 and threw 20 touchdowns against six picks during a standout rookie campaign. He was then in line for a rosy playoff matchup against the Seahawks and their lousy pass defense, but he struggled. Marino threw two picks, and the Dolphins blew a 20-17 fourth-quarter lead to lose.
Russell Wilson (2012 Seahawks, 117 AY/A+) led a pair of playoff comebacks. He brought the Seahawks back from 14-0 down against Washington, albeit with a significant amount of help from Marshawn Lynch, who ran for 132 yards and a touchdown. The following week, Wilson and the Seahawks went down 20-0 at halftime in Atlanta, only for Wilson to guide the Seahawks back with a ridiculous second-half flurry, going 14-of-19 for 241 yards with two passing touchdowns and a rushing score. The Seahawks took the lead at 28-27 with 31 seconds left, only for their defense to give up a pair of big plays to Matt Ryan before a successful field goal from Matt Bryant regained the lead for the Falcons. Wilson finished up by throwing an interception on a Hail Mary to, of all people, Julio Jones. And hey, speaking of ...
Matt Ryan (2008 Falcons, 114 AY/A+) didn't have his best game on the road in Arizona during the wild-card round. Ryan threw for 199 yards on 40 attempts against the league's 26th-ranked pass defense, mixing in two passing touchdowns with two interceptions, a fumble and a safety. A Ryan score with 4:15 left got Atlanta within six points at 30-24, but Arizona succeeded at keepaway during their four-minute drill and Ryan never saw the ball again.
The only other qualifying player with an above-average AY/A+ is CFL legend Dieter Brock, who spent his lone season in the NFL posting a 107 AY/A+ as a 33-year-old rookie with the Rams before going 10-of-31 for 66 yards with a pick against the '85 Bears in the conference championship game, after which Brock retired with a back injury. Following Brock is Joe Flacco, who posted a 99 AY/A+ (average is 100) in 2008 and then went 2-1 in the playoffs despite averaging all of 140.3 passing yards per game. The Steelers harassed him into a three-interception day in the AFC Championship Game.
Many of these quarterbacks played like stars as rookies and turned into franchise quarterbacks after their rookie campaign. Almost all of them struggled to avoid giveaways against the tougher competition of the postseason, and it eventually sunk most of their teams, with Wilson the lone exception.
Prescott has avoided giveaways for most of the year. The only quarterback by these criteria with a better era-adjusted interception rate (INT%+) is Marino, which represents very solid company. It seems unlikely that Prescott will have a three-giveaway day, something that didn't happen even once to him as a rookie.
The other unspoken element of all this is that the Cowboys have an insurance policy most other teams couldn't expect to enjoy: a superstar-caliber quarterback on the bench in Tony Romo, who looked solid leading a touchdown drive during his season debut in Week 17.
The idea of turning things over to Romo is beautiful if you're a member of the media covering the Cowboys, but I don't think it's likely. Prescott is this team's starting quarterback for years to come, and if Dallas benches the rookie, the emotional effects could last long after one game. The historical numbers for rookies in the playoffs are discouraging, but Prescott has been so effective as a rookie that they deserve to be applied with many grains of salt.
If any rookie can make magic happen in January, it's going to be Prescott.