Andy Dalton is playing the best football of his life as his undefeated Bengals travel to Pittsburgh this weekend. But this isn’t the first time he’s gotten hopes up in Cincinnati

Editor’s note: Each week throughout the 2015 NFL season, The MMQB will publish an advanced analytics story by Neil Hornsby, the president of football operations at Pro Football Focus.

There’s an amusement park a few miles up the interstate from where I live in Cincinnati called Kings Island. Over the past few years, it’s been suggested by many that a new attraction should be built: The Dalton Coaster. If you constructed it based on the extreme and unexpected peaks and troughs of Andy Dalton’s play, it would be the scariest ride imaginable.

Just think of how you could label different parts of the blueprint: During a Week 10 Thursday night game against the Browns in 2014, the Bengals quarterback descended into the stygian depths of a 0.0 QB rating when under pressure. Ten days later, it was almost impossible to find an errant throw against the Saints.

As if it’s in his DNA, there seems to be a new, unfathomable series of twists and turns for Andy Dalton every season that ultimately leaves fans exactly where they began: at ground zero. As the undefeated Bengals (6-0) travel to Pittsburgh, the Cincy faithful are anxiously wondering: Will this year finally be different, or is it just a matter of time before Dalton crashes and burns?

Below, I’ve laid out the case for and the case against the Bengals making a deep playoff run based on their quarterback’s play, which has been uncharacteristically steady this season.

The Case for a Deep Playoff Run

A New Andy Dalton

At Pro Football Focus, because we grade every throw a quarterback makes, we have a unique metric. We call it the “Game-Changing Index.” Those passes that meet certain criteria on either end of the scale, we assign the names “Big Time Throw” (BTT) and “Turnover Worthy Pass” (TWP). A BTT is a well-placed downfield throw that at very best a good QB may make four to five times a game. A TWP is exactly as advertised, even if it doesn’t result in an actual turnover; it’s a throw that could easily have been intercepted—a misread coverage or a pass so inaccurate that it goes to a defender.

The Game-Changing Index is simply a ratio of the two. An elite QB will generally have a ratio of 2:1 or better, while an average player is somewhere about 1:1. Here are Dalton’s ratios for the last three years and how they compare to the league’s best.

Season Dalton’s BTT Dalton TWP Dalton’s Ratio NFL’s Best Ratio 2013 41 30 1.37 Peyton Manning

(3.31) 2014 23 22 1.05 Aaron Rodgers

(2.40) 2015 20 4 5.00 Andy Dalton

(5.00)

(Worth noting: Rodgers ranks second in 2015 with a 4.00 ratio. Numbers are normally higher on average at this time of the year before the weather gets worse.)

Essentially, Dalton is making a lot of great throws and hardly any really bad ones a big step forward for him over a six-game stretch. In his entire career he’s never come close to being this good for this long.

Depth at the Skill Positions

Cincinnati has had good offensive players for many years, but never the amount of talented resources like they do now.

In 2013, many of today’s pieces were in place, but not all of them. Two years ago, the Bengals’ starting tight end was Jermaine Gresham, who is now with Cardinals. Thought an immensely talented player, Gresham he has always had the habit of following an outstanding play with a bad error. On Monday night, he showed a glimpse of why Cincinnati didn’t bring him back this season. There he was, finishing off a good double-team block by driving Chris Canty to the ground, only to then be stood up at the point of attack by Courtney Upshaw. Although he didn’t have any drops on Monday, he’s shelled two of 11 catchable balls this year.

The Bengals, meanwhile, have Tyler Eifert, whom PFF ranks as our second-rated tight end behind only the great Rob Gronkowski. As Sam Monson describes so well in this article, teams are still struggling to understand how best to defend the rising star. Though he’s hardly Jim Kleinsasser as a blocker, Eifert usually does enough to stay in credit with his linemen.

Another change has been at “power” back, where the starter two years ago was BenJarvus Green-Ellis. But the previously reliable runner from New England suddenly became diminished and fumble-ridden in Cincinnati, and was in the process of being replaced by the mercurial Giovani Bernard. While Bernard is an excellent player, the ideal situation for this offense is a pairing of him and a bigger “thumper” to make the hybrid power and zone-blocking scheme operate at peak efficiency. While second-year halfback Jeremy Hill has had his own fumbling issues, he’s young, fast and incredibly difficult to bring down in the open field. He and Bernard form a perfect one-two combination with a very high ceiling.

The Case Against a Deep Playoff Run

The Old Andy Dalton

The previous best stretch of Andy Dalton’s career was the four games leading up to the playoffs at the end of the 2013 season. While the Bengals lost to the Steelers in Week 15, Dalton played pretty well but his receivers dropped five passes. During the other three games of that stretch, the Bengals blasted the Colts, Vikings and Ravens. Dalton’s +16.1 PFF grade over those games would have been good enough to rank No. 12 over the entire season.

With home-field advantage for a wild-card playoff game against the Chargers, everything was looking up in Bengaldom. Except Dalton delivered the most disappointing performance of his career to date. He couldn’t read the blitz (21.8 QB rating against), fumbled without being touched and even had his own linemen lambasting him at one stage in the proceedings. It was as horrible an ending to a season as one could imagine.

It wasn’t an exception, but the rule, which Bengals fans have come to accept as a law of physics: Andy Dalton will build us up, only to let us down.

Until the Bengals win a playoff game—and preferably more than one, and in the same postseason—many Cincinnati fans will only believe that their quarterback is setting them up for a gut-wrenching roller coaster ride.

Defensive Flaws

It’s not that the Bengals have a bad unit—they don’t—but there are concerns at every level of the defense.

Consider the secondary: While Adam Jones is PFF’s eighth-ranked corner, Dre’ Kirkpatrick is No. 107. He has the worst tackling efficiency in the league, having missed 33% of all the tackles he’s attempted.

Consider the linebackers: When Vinny Rey went down with an ankle injury against the Bills in Week 6, it depleted an already mediocre group. Anything that forces the Bengals into using A.J. Hawk and, in particular, Emmanuel Lamur (our lowest graded 4-3 OLB) more frequently is not helpful.

Consider the defensive line: The guys up front have their strengths, but after seeing a blistering start to the season from Geno Atkins, his play against the Bills was a little disappointing. This will need this to be a blip rather than a trend, because interior pressure will be almost non-existent without him.

Now everything will be tested in Week 8. If the Bengals beat Pittsburgh and Dalton plays well, we might keep focusing on his climb rather than an eventual fall. If they lose, of course, it’ll only be one game and there’s still plenty of time for Cincinnati to get everything right.

Neil Hornsby is the president of football operations at profootballfocus.com.