Football has never seemed so dominant, in ratings or in popular culture. Despite this, some believe the NFL is heading for a dramatic fall and that football culture itself is suffering from a disease that is literally fatal.

Tonight's "Frontline" documentary, "League of Denial: The NFL's Concus sion Crisis" (9 p.m., PBS), has already made news. Just this summer, ESPN backed away from its association with the film, allegedly under pressure from the NFL.

The danger of playing football and taking hard hits is hardly news. The film deals with the accumulation of evidence that playing football leads to brain damage and dementia, and the gnawing concern that the NFL was aware of this and has tried to deny or deflect the evidence so as to avoid legal obligation to the growing ranks of ex-players seeking medical care and compensation. Like many media scandals, it boils down to what the NFL knew and when its leaders knew it.

Some people are going to dismiss "League" as another battle in the culture wars, an attempt by Chablis-sipping sophisticates to destroy America's game. To counter that impression, "Denial" begins with the story of Mike Webster, a 17-

year veteran of Pittsburgh's

beloved Steelers. As his fellow players recall, Webster played center with his head -- using it as a battering ram. And the steady pummeling would shatter his mind, render him homeless and kill him by 50.

In a tragic twist, it would be Webster's head, or rather the scientific study of his preserved brain, that first led doctors and regulators to seriously question the NFL's culture of organized violence.

One expert estimates the G-force impact of playing impact-heavy football is the equivalent of driving a car at 30 mph into a wall. And doing it more than a thousand times a year.

In a harrowing story, Leigh Steinberg, the super agent who inspired "Jerry Maguire,"

describes how Troy Aikman's frightening post-concussion

behavior utterly changed his mind about the value of the game.

The NFL recently settled a deal with more than 4,200 players claiming brain damage. But this does not quiet a growing chorus of people, including former players, willing to publicly declare they might not allow their own children to play football.

Sometimes it takes a gener-

ation or more to change a culture. Remember when cigarette smokers were cool? In many ways, the growing list of former NFL stars who have receded into dementia and early graves is reminiscent of the many famous smokers to die before their time. It may take years, but people tend to learn by

example.

---TV-themed DVDs available today include "Robot Chicken Season 6."

SEASON PREMIERES

---"The Biggest Loser" (8 p.m., NBC) returns.

---Sam receives a grim prognosis on "Supernatural" (9 p.m., CW, TV-14).

OTHER HIGHLIGHTS

---Plans unravel on "Marvel's Agents of S.H.I.E.L.D." (8 p.m., ABC, TV-PG).

---Jake's new crush on "Brook lyn Nine-Nine" (8:30 p.m., Fox, TV-PG).

---Mixed signals on "Person of Interest" (10 p.m., CBS, TV-14).

---Strange bedfellows on "Sons of Anarchy" (10 p.m., FX, TV-MA).

---Severide doubts arson evidence on "Chicago Fire" (10 p.m., NBC, TV-14).

CULT CHOICE

A rich widow (Jane Wyman) falls for a younger horticulturalist (Rock Hudson) in the 1955 melodrama "All that Heaven Allows" (10 p.m., TCM).

SERIES NOTES

---Twitter to the rescue on "NCIS" (8 p.m., CBS, TV-PG).

---Eli dates a standup on "Dads" (8 p.m., Fox, TV-14).

---A Crescent City surprise on "The Originals" (8 p.m., CW, TV-PG).

---A risk to public health on "NCIS: Los Angeles" (9 p.m., CBS, TV-14).

---Jealousy rages on "New Girl" (9 p.m., Fox, TV-14).

---Barry goes to work on "The Goldbergs" (9 p.m., ABC, TV-PG).

---Morgan makes a claim on "The Mindy Project" (9:30 p.m., Fox, TV-14).

---Hillary fibs on "Trophy Wife" (9:30 p.m., ABC, TV-PG).

---More than a jackpot on "Lucky 7" (10 p.m., ABC, TV-14).

LATE NIGHT

---Malala Yousafzai is scheduled on "The Daily Show With Jon Stewart" (11 p.m., Comedy Central).

---Lisa Kudrow, Diego Luna and Florida Georgia Line appear on "Conan" (11 p.m., TBS, r).

---Sarah Silverman is scheduled on "Totally Biased With W. Kamau Bell" (11 p.m., FXX, r).

---Paul Giamatti sits down on "The Colbert Report" (11:30 p.m., Comedy Central).

---Seth Meyers, Michael Fass-

bender and Amos Lee appear on "Late Show With David Letter man" (11:35 p.m., CBS).

---Jay Leno welcomes Billy

Crystal, Snooki and JWoww and Toni Braxton & Kevin "Babyface" Edmonds on "The Tonight Show" (11:35 p.m., NBC).

---Elton John appears on "Jimmy Kimmel Live" (11:35 p.m., ABC).

---Miley Cyrus visits "Late Night With Jimmy Fallon" (12:35 a.m., NBC).

---Craig Ferguson hosts Sarah Michelle Gellar and Guillermo Diaz on "The Late Late Show" (12:35 a.m., CBS).

Kevin McDonough can be reached at kevin.tvguy@gmail.com.