While the NFL might be America's game, it can occasionally be as incomprehensible as cricket.
There's the coded lingo quarterbacks shout at the line of scrimmage. There's the league's complex salary cap. There's Dan Snyder.
But for me the league's least understandable element is something that ought to be simple to explain but never really has been:
Why does the richest sports entity in the universe have the lowest average salary of any of the four major professional sports leagues?
The NBA's average salary is $5.15 million. In MLB, it's $3.2 million, and in the NHL - a niche sport compared to football - it's $2.4 million.
Yet in the NFL, despite its monster TV ratings, its sold-out stadiums, and its awesome marketing machine, the average player makes $1.9 million a year.
That figure is counterintuitive on so many levels.
Revenue certainly doesn't explain it. The average NFL team, according to Forbes, pulls in an average of $206 million annually and is worth $1.47 billion.
That annual revenue is more than double what an NHL club makes, $84 million more than the NBA's average, $12 million better than baseball's.
And you would think that since pro football's athletes have the shortest career span in sports, its salary structure would help compensate for that shortcoming.
The average NFL player plays just 3.2 years, while a baseball career lasts 5.6 years, hockey 5.5, and basketball 4.8.
Part of the reason is the relative weakness of the NFL Players Association. Salaries haven't increased anywhere near as rapidly as the values of the teams.
Take the Eagles as an example.
Jeffrey Lurie bought the team from Norman Braman in 1994 for $195 million. Twenty years later, according to Forbes, the Eagles are worth $1.75 billion. That's an increase of approximately 900 percent.
Meanwhile, the average NFL salary in 1994 was $628,000, meaning it's risen only by about 300 percent.
Amid all the hand-wringing about football's future in the face of its head-injury epidemic come some surprising numbers.
According to the National Federation of State High School Associations, after a four-year decline, the number of high-schoolers participating in football increased during the 2013-14 school year.
There were 1.09 million boys (and 1,700 girls) playing high school football last year, down a few hundred thousand from 1977's record levels but up several thousand from 2012-13.
This positive bump comes amid all the negative concussion publicity.
A recent survey found that an all-time high of 44 percent of American parents said they'd be uncomfortable allowing their children to play football.
But there's a reason that unease hasn't translated into fewer high school players. Only 5 percent of those uncomfortable parents said they would actually stop their child from participating.
Speaking of head injuries, it seems that, in the NFL at least, speed rather than mass is the common denominator.
The most frequently concussed positions, according to statistics compiled by the NFL, are, in order, wide receivers, cornerbacks, safeties, tight ends, and running backs.
The safest spots are fullback, center, and defensive tackle.
Despite the sobering critical and financial lessons provided by such now-deceased entities as the World Football League, the U.S. Football League, and the XFL, there's another professional football league out there.
The new Fall Experimental Football League is a modest entry. It has just four teams and only three home cities. While Boston, Brooklyn, and Omaha host franchises, the fourth team, the Blacktips, is nomadic, traveling from city to city.
The FXFL, as its name implies, sees itself as developmental, even though the NFL already has its own system of practice squads and has long used NCAA football as its personal player assembly line. Players on its 40-man rosters earn between $1,000 and $1,250 a game.
If history is any guide, the best the FXFL can hope for is that someday the NFL will adopt some of its innovative rules. They include:
Extra points from 35 yards out.
A requirement that all 40 players participate in each game.
Kickoffs from the 25-yeard line, with eight players on the receiving team between the kicking team's 35- and 45-yard lines.
Who says stats don't lie?
How truly significant are . . .
. . . interceptions, when the Eagles are tied for the league lead with 16 and are 9-3? Meanwhile, the team they're tied with, Jacksonville, is 1-10.
. . . tackles, when four of the league's top five tacklers play on losing teams in the NFL's worst division, the NFC South?
. . . completion percentage, when NFL leader Drew Brees' Saints are 4-7?
. . . average yards per catch, when DeSean Jackson, of the 3-8 Redskins, is No. 1?
. . . punting average, when those same dreadful Redskins also have the kicker (Tress Way) who tops the NFL with a 48.6 per-yard average?
TOP EARLY GAME
Cleveland at Buffalo
The Thanksgiving triple-header stripped early Sunday of most of its glamour, but this matchup of two of the league's surprises figures to be both competitive and interesting. In pro sports, only the Toronto Blue Jays have been without a playoff appearance longer than the 6-5 Bills. The 7-4 Browns have the fourth-longest drought.
TOP LATE AFTERNOON GAME
New England at Green Bay
You don't need a wild imagination to see this one as a potential Super Bowl preview. The 9-2 Patriots may be playing better than anyone in the league, and the 8-3 Packers have been a juggernaut at home. QBs Tom Brady and Aaron Rodgers have combined for 56 TD passes and just nine interceptions.
Denver at Kansas City
Another intriguing matchup, but this one between teams with wildly divergent styles. The 8-3 Broncos lost two weeks ago to the Rams, then had to rally at home to outlast Miami. The 7-4 Chiefs were upset in their last game by the Raiders. How effectively and how long Alex Smith, Lorenzo Charles, and the Chiefs control the ball, keeping it away from Peyton Manning, will be the key.
Miami at N.Y. Jets
While the 6-5 Dolphins are still competing for a wild-card spot, the 2-9 Jets have abandoned their season. Proof of that - as well as of Michael Vick's ineffectiveness - is New York's decision to return Geno Smith to the starting QB job for the rest of the season. Miami blew a big lead at Denver last week and needs a psychological bounce-back.