Although the 2019 NFL season isn’t quite over yet, all of the head coaching slots for next year have now been filled. The final piece of the 2020 coaching puzzle slid into place on Sunday when it was reported that the Cleveland Browns planned to hire Vikings offensive coordinator Kevin Stefanski for their top job. Stefanski became the fifth coach to fill a vacancy this month, joining Matt Rhule (Carolina), Mike McCarthy (Dallas), Joe Judge (N.Y. Giants) and Ron Rivera (Washington).

Only one of those coaches, however, is not a white man. And while Rivera is Latino, he was fired from Carolina’s job in early December — so his hiring doesn’t represent a net increase in NFL coaching diversity year-over-year. In the NFL, 59 percent of players are black and 70 percent are nonwhite, according to The Institute For Diversity And Ethics In Sport (TIDES). But only 12.5 percent of regular-season NFL games this past season were coached by people of color, a share that will hold steady to start the 2020 season.

It’s a discouraging trend and a major decrease from the 25 percent level seen in 2017, which at the time was hailed as a sign of the progress made by minority coaches in their decades-long struggle for recognition and influence on the sidelines. (The all-time high-water mark for coaches of color was 27.1 percent of games, set during the 2011 season.)

Last year’s hiring cycle was marked by a suspicious demographic commonality among new coaches, often linked to teams’ seeming fixation on finding their own version of Los Angeles Rams coach Sean McVay. And from the data, it was hard not to come to that conclusion. Eight new coaches were hired; among those, four were replacing black coaches (five if you count Hue Jackson, who had started the season as Cleveland’s coach), and only one of the incoming group (Miami’s Brian Flores) wasn’t white. Like McVay, six came from offensive backgrounds — where there is a notable dearth of minority coaches among the top assistant ranks.

So when it came to hiring new head coaches, there didn’t seem to be much room for those who didn’t fit that particular mold. “There are so many qualified minority coaches,” former Steelers wide receivers coach Darryl Drake told NFL.com’s Jim Trotter last summer. “A lot of guys felt slighted in this last hiring cycle. A lot of guys do not know which road to take to get their names in a position to where they can have those opportunities. A lot of guys felt like certain individuals that should have had opportunities to get a job did not get a job.”

This time around, there wasn’t as much of an overarching trend across the new hires, except that minority coaches weren’t able to make any progress. A number of the incoming coaches had less experience and/or were coming from a lower place in the coaching ranks than Kansas City Chiefs offensive coordinator Eric Bieniemy, for instance, who should have been considered one of the best head coaching candidates on the market. (Judge, by contrast, was previously just the wide receivers coach for the Patriots; Rhule is a college coach with only a single season of NFL experience. Stefanski holds the same position as Bieniemy, but his team scored just 10 points en route to a playoff elimination, while Bieniemy’s put up 51 in a come-from-behind win.)

Increasingly, black coaches are going into interviews feeling like they have no shot at getting the job.

If NFL coaching diversity seems to have hit a wall in recent years, it’s oddly reminiscent of the way early progress stagnated before the league originally adopted the Rooney Rule — which requires that teams interview at least one minority candidate for any head coaching job vacancy — back in 2003. Research by the late economist CC DuBois showed that the Rooney Rule did actually have a positive effect on coaching diversity, compared with NCAA coaches and NFL coordinators, who did not have similar interview requirements. You can trace an almost continuously rising line from 2002, when only 6.3 percent of games were coached by people of color, to that 27.1 percent number from 2011, and surely the Rooney Rule played a major role in the increase.

But the effect of the Rooney Rule appears to be wearing off over time — and it might be time to rethink the entire process. Increasingly, the perception is that owners have made up their minds about head-coaching hires before even speaking with minority candidates. As ESPN’s Mina Kimes wrote a few years ago, white assistant coaches are 114 percent more likely to be promoted to the coordinator level than black coaches managing the same position, so the pool of potential candidates is falling behind as well. And in college, black coaches are continuously given fewer chances to overcome disappointing seasons. What good is an interview quota at the top if every other rung on the ladder is broken?

There are no quick solutions, but after a third straight hiring cycle where the NFL’s minority head coaching ranks failed to grow to better resemble the demographic makeup of its player base, it seems like the league is due for another significant change in the way it approaches coaching diversity.