Whatever momentum the Minnesota Vikings were riding after last year’s surprise division title has vanished with Tuesday’s devastating injury to starting quarterback Teddy Bridgewater’s knee. Although he was fortunate the damage wasn’t even worse, the ACL injury will cause Bridgewater to miss the entire 2016 season.

It’s not that Bridgewater was great last season; he was below average in passing-efficiency metrics such as adjusted net yards per attempt and Football Outsiders’ defense-adjusted value over average. But he was decent, and more important, still young. Bridgewater turned 23 last November, and that combination of youth and competence typically sets a quarterback up for at least a solid career, with room to develop into something greater. Long-term potential is something the Vikings have sorely lacked from their passers in recent years.

One way of measuring a young quarterback’s promise is to find historical passers who produced similar statistics at the same age, and track how those players’ careers ended up panning out. To that end, I gathered seasonal data on every player to throw a pass in the NFL or AFL during the Super Bowl era (since 1966), and translated it to a common standard: a 16-game season with the NFL’s typical passing environment since offensive rules were liberalized in 1978. I then plugged those numbers into Football Outsiders’ similarity score formula for quarterbacks, returning a list of the 20 most similar QBs for any given passer’s season.

For Bridgewater, that list looked like this last season:

TRANSLATED PASSING APPROX. VALUE RANK YEAR QUARTERBACK AGE ATT YDS TD/INT THRU YEAR AFTER YEAR — 2015 T. Bridgewater 23 405 2757 11/12 22 — 1 1978 D. Whitehurst 23 403 2741 13/13 10 11 2 1990 T. Aikman 24 429 2755 11/19 9 113 3 2008 J. Flacco 23 430 2926 15/15 11 77 4 1973 A. Manning 24 407 2770 15/12 25 68 5 1971 D. Shaw 24 417 2768 16/22 11 9 6 1972 D. Shaw 25 386 2605 19/17 18 2 7 1982 N. Lomax 23 375 2535 9/9 15 67 8 2000 S. King 23 422 2785 19/14 16 2 9 2001 T. Couch 24 451 3073 18/21 20 12 10 2013 R. Griffin 23 417 2829 14/14 28 5 11 2006 A. Smith 22 448 2935 17/18 7 76 12 1995 T. Dilfer 23 387 2614 4/19 7 53 13 1997 T. Dilfer 25 382 2633 22/12 27 33 14 1984 J. Elway 24 385 2625 17/13 14 189 15 2008 T. Edwards 25 376 2658 12/12 13 5 16 2001 T. Brady 24 410 2874 19/12 12 211 17 2004 B. Leftwich 24 447 2905 14/11 18 18 18 2013 C. Newton 24 433 2984 20/15 51 32 19 2014 T. Bridgewater 22 373 2565 12/15 9 13 20 2006 J. Losman 25 434 3098 20/15 14 6 Most similar passing seasons to Teddy Bridgewater’s 2015 season Sources: Football Outsiders, Pro-Football-Reference.com

The names on Bridgewater’s comp sheet illustrate the myriad directions in which a young quarterback’s career can drift, even after two solid NFL seasons. Troy Aikman and John Elway became Hall of Famers, and Tom Brady will join them in Canton someday. Joe Flacco, Archie Manning and Neil Lomax all flashed greatness at various times in their careers but didn’t maintain that level of play throughout. Trent Dilfer and Alex Smith salvaged the lost promise of their youth to become semi-successful journeymen, and Tim Couch and J.P. Losman were outright busts. The book on Cam Newton’s career is far from written.

For a quarterback-rich franchise such as the Colts or Packers, the above list probably wouldn’t inspire a lot of enthusiasm about Bridgewater. For the Vikings, though, it represents a huge change from their recent fortunes. One way we can measure that is by looking at the Approximate Value (AV) that Bridgewater’s comps produced over the remainders of their careers. After weighting by their similarity to Bridgewater and making a slight adjustment for the fact that Bridgewater had more career AV through the season of comparison than his comps did, , Bridgewater’s comps were good for about 46 AV in their remaining careers. Ever since the last premerger starting QB retired in 1981, the average NFL starter has consistently hovered around 40 points of future expected AV, so Bridgewater’s potential was better than the norm going into this season. And that was a big deal for the Vikings, who hadn’t featured a QB with such potential since Daunte Culpepper posted a brilliant season in 2004 (before falling apart the next season).

Aside from the brief blip of Christian Ponder in 2012 — who gleaned 43 expected future AV out of an eclectic comp list that included Kordell Stewart (maybe the algorithm matched them because neither knew how to throw a football?) and Troy Aikman, plus Dilfer and Dave Brown — Culpepper was the last Viking passer with above-average potential before Bridgewater came along. And those three joined Randall Cunningham (right after his amazing 1998 resurgence) and Brad Johnson (from his first year at the team’s helm, in 1996) to create the only moments a Minnesota QB flashed superior potential in the last 28 years. The division-rival Packers have had a starter crack 40 AV of potential in a league-best 19 of the 23 seasons since the NFL’s free-agency era began in 1993; Minnesota’s topped average less than half as often.

And with Shaun Hill now leading the Vikings’ depth chart, that trend is unlikely to improve. (Hill’s rest-of-career projection after last season: 1.9 AV.) Bridgewater hadn’t yet joined the elite ranks of NFL signal-callers, but he offered Minnesota the next-best thing: real potential. It was a rarity for the franchise, and a promise that will now have to remain on hold for another season.