Your average NFL team? Well, they’re all about average

The NFL isn’t a league of haves and have-nots, it’s closer to 32 half-decents.

The best teams aren’t that great, and the worst teams aren’t that bad.

A week ago, it looked as if the San Francisco 49ers couldn’t lose. They had beaten their previous two opponents by a combined 79-3. Then, they were nearly shut out at home by the New York Giants, 26-3.

The same Giants who are already 0-2 in the NFC East.

The Houston Texans and Baltimore Ravens will battle Sunday for supremacy in the AFC, yet both have lost some of their best defensive players. The Texans are fresh off a pounding from the Green Bay Packers, who have yet to win consecutive games.

The league’s only undefeated team, the Atlanta Falcons, won by a combined five points at home over a pair of one-win teams, Carolina and Oakland.

Just as in this year’s baseball playoffs, with seemingly every game hinging on the final at-bat, the unpredictability of the NFL is riveting.

Just ask the bettors in Las Vegas. According to betting expert R.J. Bell, NFL underdogs have covered in 64% of the games this season — only the second time since 1989 that underdogs have covered in more than 60% of the games.

“The reality of the NFL is that there’s greater parity than the public believes,” said Bell, founder of Pregame.com. “With the underdogs winning, it shows the public is overestimating the difference between the favorites and the underdogs. The parity is stronger than ever.”

And so is the betting action. Bell said this NFL season is on track to be the biggest in Nevada history in terms of amount of money wagered.

Bell added that a survey of bettors and bookmakers in Las Vegas determined that New England is “clearly the best team” in the league … and yet the Patriots are a mediocre 3-3, fresh off a loss at Seattle.

In another odd twist, the Patriots have outscored opponents by 51 points, the Buffalo Bills have been outscored by 55, and they’re both 3-3. All the AFC East teams have the same record, in fact, marking the first time since realignment in 2002 that there’s a four-way tie for first place in a division this far into a season.

So what’s the reason for all this competitive balance? Why are there so many tossups?

It’s partly the proliferation of talented young quarterbacks, with a record five rookies opening the 2012 season as starters. Think about the success those first-year players have had, and the leveling effect it has on the league. Washington beat New Orleans with Redskins rookie Robert Griffin III at quarterback. Indianapolis and Andrew Luck beat Green Bay. Seattle and Russell Wilson beat the Patriots.

There are other reasons too. Some of the Hall of Fame-bound quarterbacks are entering the twilight of their careers: Tom Brady, Peyton Manning, Drew Brees. The Saints, previously an elite team, have been slapped down by sanctions. And the introduction of early-season Thursday night games can be an equalizer that takes the edge off a good team.

As it is, the difference between winning and losing in the NFL often boils down to three or four pivotal plays — and it’s not easy to predict which team will make them.

In other years, when there has been a true spectrum of teams, the elite on one side, the dogs on the other, and the majority somewhere in between, it was easy to spot which matchups would be interesting.

“When that piece of paper comes out in April with our schedule on it, it used to take me about two minutes to glance through it and see which ones would be blockbusters,” said ESPN’s Jay Rothman, “Monday Night Football” producer. “But as soon as there’s a game that doesn’t catch your eye, that’s when the magic happens.”

In a sense, the magic happened over and over in Week 6, with underdogs going 12-2 against the spread — a record that has been matched only one other time since 1989.

On a personal note, I did even worse than those 2-12 favorites, going a forehead-slapping 1-11-2 against the spread.

A reader wrote to joke that, after using my picks, he was moving into a cardboard box.

My message back after another head-spinning, logic-defying week in the NFL:

Scoot over if there’s room.

sam.farmer@latimes.com twitter.com/LATimesfarmer