How on Earth are Cowboys fans supposed to have reasonable expectations for Dak Prescott?

The rookie quarterback has outperformed them all so far, leaving us to question our preconceptions about what fourth-round draft picks can accomplish at the league's most impactful position.

But this isn't another Prescott puff piece. As great has he's been—Prescott ranks third among NFL quarterbacks in ESPN's Total QBR metric, five spots ahead of the Eagles' Carson Wentz—past production isn't always indicative of future performance. Especially when "past production" represents only one quarter of a season.

So what can we expect from Prescott going forward? And how do we weigh that against what Tony Romo brings to the table, when healthy?

These are questions the Cowboys front office and coaching staff will have to answer. As observers, the best we can do is avoid our natural inclination toward recency bias and consider the very real challenges Prescott will face in the coming weeks:

  • Quality of opponents—In the first four weeks of play, Prescott has yet to face a Top 15 defense, according to Football Outsiders' Defense-adjusted Value Over Average metric. That will change in the next three games, as the Cowboys host the Cincinnati Bengals (No. 7 in defensive DVOA), travel to Lambeau Field to play the Green Bay Packers (No. 10) and host the Philadelphia Eagles (No. 2) after the bye week. Although Romo could return in time for the Eagles matchup, Prescott will face at least two games in a row against defenses the likes of which he has probably never competed against in his life.
  • Game tape—Early on in the season, Prescott undoubtedly benefited from defenses' unfamiliarity with his game. The best that opposing defensive coordinators could do until now is analyze his tendencies from college at Mississippi State and a few dozen snaps against professionals. As time goes on, Prescott is almost certain to run into defenses that gameplan to exploit his weaknesses and force interceptions—something the hapless Chicago Bears and San Francisco 49ers were unable to do the past two weeks.
  • Accuracy issues—Prescott's accuracy has been nearly perfect within 15 yards of the line of scrimmage. Beyond that, we've seen repeated instances of receivers having to adjust their routes to catch Prescott's passes downfield, particularly on under-thrown passes where a defensive back is beaten near the goal line. Other throws have sailed over receivers' heads and out of bounds. This might sound like nitpicking, given Prescott's inarguably successful outcomes so far. But his accuracy is a factor that could come back to bite the Cowboys, particularly in late-game situations while playing from behind.

The Cowboys have to be thrilled with Prescott at this stage, and he's earned every bit of excitement from the fans who hope he can be the team's future at quarterback. He has shown poise and decision-making that have impressed the coaching staff and bolstered confidence from his teammates.

But in the meantime, I'm of the opinion a healthy Romo is still the significantly better option to lead this team to—and through—the playoffs. Romo's ability to read the defense before and after the snap, downfield accuracy and willingness to take calculated situational risks place him among the rarest of company in his generation of quarterbacks.

And I can guarantee you Cowboys opponents would take their chances with the rookie before they would risk being carved apart once again by Romo.

Chart of the week:

A quarter of the way into the season, we have yet to see what this team can ultimately become.

The Cowboys are bound to play more difficult opponents that force us to reassess the strengths and weaknesses of the team. That said, certain trends are emerging that give us a pretty decent idea of how this team compares to the Cowboys from years past.

The chart below gives us a window into how each unit has contributed to the team's scoring margin per game, according to Pro Football Reference's expected points model:

The most obvious observation here: The Cowboys passing attack was incredibly good with Romo in 2014; incredibly bad under Matt Cassel and Kellen Moore in 2015; and has been pretty darn good in only four games under Prescott.

The Cowboys have also done a very good job taking care of the ball so far this year, handing over an unsustainably low number of offensive turnovers. They've also done a better job of producing turnovers than last year's abysmal total.

I continue to argue—and the expected-points data backs this up—that the Cowboys must improve their pass defense to give Romo a chance to make a deep playoff run. In the last two weeks, the pass defense has done a much better job, although admittedly against inferior opponents. It will be interesting to see whether this trend continues as the returns of DeMarcus Lawrence, Orlando Scandrick and possibly second-round pick Jaylon Smith loom.

Would you stick with Dak or go back to Romo when he's healthy? Let Daniel know on Twitter @Daniel_Houston.