What would we armchair psychiatrists do without Brett Favre?
He is forever providing fodder for our amateur diagnoses. We cannot resist exploring beneath his grey hair and into his grey matter, wondering what motivates the Minnesota Vikings quarterback whose body and mind belong in a science laboratory as much as his jersey does in the Hall of Fame.
Why does he waffle each off-season over retirement?
Why does he throw into the teeth of defences, unable to resist the pass with the highest degree of difficulty?
Why does he - at 41, the oldest non-kicker in the NFL, married with a family - send unsuitable (and easily traced) text messages to a 20-something woman?
And now: why did he drag a fractured ankle on to the field on Sunday against the New England Patriots when sitting out would not tarnish his legacy?
To the legions of Favre-bashers, he played despite a broken ankle because he was driven to extend his record consecutive-starts streak to 292. That is, he was burnishing his resume while hurting his team's chances of victory.
Funny. We used to celebrate such grit, dating to baseball's Lou Gehrig, who was dubbed the "Iron Horse" in tribute to his 2,130 games without a break.
Gehrig became the archetype of the admired athlete imbued with a work ethic to which the 9-to-5 set could relate.
Ice hockey had Doug Jarvis and his 962 games, professional basketball had AC Green and his 1,192 in a row.
No contemporary games-played streak caught America's fancy like Cal Ripken Jr's 2,632 without a break for baseball's Baltimore Orioles.
The run-up to Favre's game last Sunday spawned debates over who was the greatest hero to the blue-collar brigade and the perfect-attendance society in our schools.
In a call so close that we might need an instant replay, the nod here goes to Favre. Granted, a football player is afforded a week between games, and a combination of adrenalin, high pain tolerance and pharmaceuticals can carry him through the day.
Yet football guarantees more physical punishment than baseball unless you are a back-up holding a clipboard, a job choice Favre eschewed.
Ripken, though praiseworthy, was blessed with a career almost devoid of injury. And, let us be honest, a player can coast through a baseball game or two even if something minor-to-middling ails him.
Still, we can make a case for Ripken over Favre. The United States Supreme Court would see it 5-4, either way.
Ripken's remarkable stretch of endurance was not universally applauded. Some eventual critics removed their rose-tinted glasses and noted that his slump late in the 1989 season corresponded with a stretch of defeats that cost the Orioles a division title.
Had he taken a break or two, the thinking goes, the Orioles might have reversed the outcome of a few losses that season, and beyond.
Ripken's career peaked in 1991 with an MVP season, then went into a gradual decline until he took a day off seven years later.
In 1993, Bobby Bonds, then the San Francisco Giants coach, was quoted as saying: "If I were his manager, he'd be out of there. He wants to break Lou Gehrig's record, even if it'll cost Baltimore the pennant."
Though Bobby was the father of the controversial slugger Barry Bonds, which might qualify him as a guilt-by-association dummy, his perspective ultimately was seconded by respected baseball men. From all indications, Orioles managers bowed to Ripken's desire to chase Gehrig's record.
The same analysis has been applied to Favre. Brad Childress, his coach, is widely assumed to have turned over the get-hit-or-sit decision to the player.
Unless Childress is head-over-heels beholden to Favre, that makes no sense. The Vikings were 2-4 entering the game.
Favre is not coming back - honest - next season. Childress, however, presumably would prefer to remain in the employ of the Vikings next season, and to advance that cause his team needs to win more games.
He would not jeopardise his future by sending out a lame oldie against his better judgement.
Favre, even with an indifferent Randy Moss to deal with on that diva's last day as a Viking, completed 22 of 32 passes with just one interception. While delivering only 10 points in three-and-a-half quarters, he had reached the Pats' three-yard line, close to a touchdown that would have shaved a 21-10 deficit to a possible field goal.
Then Myron Pryor's helmet viciously, if inadvertently, lacerated Favre's chin, leading to 10 stitches - and 10 times as much scrutiny, -in the wake of a 28-18 defeat.
When asked whether he was concussed he replied: "I remember everything, unfortunately."
As for playing this week: "I'll be fine."
What a relief to us armchair psychiatrists. Without Favre, we might be left to dig into the scrambled brain of Moss.