The Vikings have begun training camp, ushering in the usual blend of irrational optimism and existential dread.

Which view is more closely aligned to reality?

We might not know until we see Kevin O'Connell and a new coaching staff operating under game conditions.

We might not know until the end of their first season.

History indicates that we might not know until the end of their second season.

New coaches tend to create true believers among the fan base. Remember, before Brad Childress became persona non grata, he was viewed by Vikings fans as a combination of Andy Reid and Bud Grant.

And Childress did wind up winning plenty of games. But in his first season, he took a team that had finished 9-7 under Mike Tice and went 6-10 while trying to prove that the off-tackle run was the height of play-calling genius.

O'Connell inherits a team that finished 8-9 last season. If he can spark any improvement, the Vikings should be a playoff team.

How much improvement should be expected?

Vikings history, and especially recent Vikings history, indicates that first-year coaches have a coin-flip chance of improving their team immediately, and that more dramatic improvement tends to occur in their second full season on the job.

Mike Zimmer won over the fan base immediately. In reality, he merely improved the Vikings from Leslie Frazier's final season by 1 ½ games, from 5-10-1 to 7-9. In his second season, he went 11-5 and failed to win a playoff game only because of Blair Walsh's cold-weather shank.

Frazier took a team that went 6-10 — 3-7 before Childress was fired — and went 3-13 the next season as Christian Ponder imploded. In his second full season, he went 10-6 and made the playoffs.

Childress went from 6-10 to 8-8 to 10-6 to 12-4 before the 12th man in the huddle became his Waterloo.

A year after the Vikings went 5-11 —5-10 before Denny Green was fired — Tice went 6-10. The next year, Tice went 9-7.

The last four Vikings coaches were a combined 3 ½ games worse in their first season than their teams finished the year before they took over. They were a combined 16 games better in their second full season than they were in their first.

It's easiest to be optimistic about first-year head coaches because they haven't lost — or called a failed fourth-down play, or seen a fake punt backfire in front of millions of TV viewers.

If rationality had anything to do with NFL fandom, the biggest expectations would be saved for Years 2 and beyond.

O'Connell's mentor, Sean McVay, might be the most celebrated head coach in the league, and he did make an immediate impact in his first season.

The year before he was hired, Jeff Fisher went 4-9 in a 4-12 season to finally get himself fired.

There's a facile comparison to be made here — a bright, young offensive coach (McVay, O'Connell) replacing a wizened defensive coach (Fisher, Zimmer) and having immediate success.

Let's not pretend Fisher and Zimmer were the same. Fisher never won more than seven games in five years as Rams coach. Zimmer never won fewer than seven.

McVay won 11 games and lost in the wild-card playoff game in his first season. In his second season, he won 13 and made it to the Super Bowl, and if Todd Gurley had been healthy, he might have had a chance to beat the Patriots.

Bill Belichick, perhaps the greatest NFL head coach of all time, went 5-11 in his first season with the Patriots. In his second season, he won the Super Bowl.

In his already-infamous interview with USA Today, new Vikings General Manager Kwesi Adofo-Mensah admitted that his quarterback, Kirk Cousins, isn't on the same plane as the greats in the game. Adofo-Mensah's willingness to share that view indicates that he views Cousins as an expensive placeholder.

The 2022 Vikings are talented enough to win 10 or 11 games. If the Green Bay Packers slip and the Vikings' key players stay healthy, they could even win the division.

But history indicates that the new braintrust, if capable, will hit their stride in Year 2 or beyond, and probably with a different quarterback.