The Jets beat the Titans a few weeks ago and were 8-3. Then they lost to the mediocre Denver Broncos and are on the verge of spitting the bit against the pathetic San Francisco 49ers. (And the reason the game is so “close” is because the 49ers are so deplorably bad — if they were remotely competent the Jets would have lost by 30 points.)

If they lose the next three games, which seems plausible, if not probable, Eric Mangini and Mike Tannenbaum should be fired.

There are a couple of reasons.

First, every NFL football team in this day and age loses a game they should win. It’s a fact of life. (Last year’s Patriots made the mistake of putting off that loss until the last game of the season.) The best teams rebound.

The Jets lost such a game to the nauseating Raiders earlier this year and responded with five wins in a row. They had clear sailing to a first round bye in the playoffs. All they had to do was keep on playing hard. Then they laid another egg against the Broncos and responded by missing the flight out to the west coast this weekend. Two weeks in a row of getting shown up by presumably inferior teams during the stretch run is on the coach.

More broadly the nature of the NFL in the era of parity is that even mediocre teams can be competitive every couple of years. Exceptional teams are competitive year in and year out. Really incompetent teams are continuously non-competitive. Like the Jets.

Can the Jets recover? Sure.

Is it likely? Next week they play the Bills, who they never beat twice in a season. Then they have to travel to Seattle. They haven’t won this year west of Nashville, losing to San Diego, Oakland and San Francisco (vomit, vomit and vomit). Then they close against a suddenly competitive Dolphins team. The likelihood at this point is that the Jets will be playing spoiler rather than battling for the divison.

So the Jets pushed all their chips into the middle this off-season, spending huge amounts of money, bringing in the (suddenly very pedestrian) veteran quarterback. If they complete their death spiral, they should drag Tangini down with them. And good riddance.