Is Kevin O’Connell Really a QB Whisperer?
The success of the Vikings’ 2025 season hinges on the play of unproven QB J.J. McCarthy. Under typical circumstances, this is an unenviable situation to be in: not even a top QB prospect is guaranteed to pan out in the NFL, and McCarthy was undoubtedly a tier below the top QB prospects Caleb Williams, Jayden Daniels, and Drake Maye in the 2024 draft class.
Yet, the Vikings have decided not to pursue a more established QB this offseason for one simple reason: their situation is far from typical.
The Vikings have one of the league’s best receiving corps in Justin Jefferson, Jordan Addison, and T.J. Hockenson, along with a newly revamped offensive line, led by tackles Christian Darrisaw and Brian O’Neill. Last but not least, the Vikings have Kevin O’Connell, a former NFL QB who is often hailed as a QB whisperer.
But is the moniker accurate? Can the Vikings really expect KOC to turn McCarthy into the next great franchise QB?
From a statistical perspective, it is very hard to answer this question fairly, though that didn’t stop me from trying. Below, I plotted the passer ratings for the six primary starting QBs with whom O’Connell has worked as an offensive coordinator or head coach (year 0), along with their passer ratings a year before KOC (year -1) and a year after leaving KOC’s tutelage (+1).
Note that Kirk Cousins has four data points because he spent two years with KOC, while Dwayne Haskins, Case Keenum, and Sam Darnold have fewer data points because they did not throw enough passes to qualify in 2018, 2020, and 2023, respectively. (Indeed, Darnold has only a single data point, which is barely visible below the peak of Stafford’s curve, since we are still awaiting the results of his 2025 season.)
The red curve shows the trend: there is a slight peak in year 0, indicating that KOC, on average, has given his QBs a boost of about 4.3 points in their passer rating. That’s a big difference…but it’s not statistically significant (p-value = 0.4).
The problem is, there are just too few data points and too many confounding factors. For instance, Matt Stafford had a much better season in 2021 under KOC than he did without KOC in 2020 or 2022, but in 2020 he was playing for a hapless Detroit Lions team, and in 2022 he was injured for nearly half the season…not exactly an apples-to-apples comparison.
So, the data is far from conclusive, but nonetheless, it is consistent with the idea that KOC and the rest of the Vikings offense will give McCarthy a meaningful boost in his first real season.
At the same time, it is also clear that KOC can only do so much: a 4.3 point boost is helpful, but it won’t take a dud and turn him into the next Lamar Jackson. At the end of the day, the success of J.J. McCarthy’s season–and the Vikings’ passing attack–falls primarily on McCarthy himself.