sports in the U.S. More people went to some championship bouts than could fit into any

NFL stadium today. But for boxing, it was all downhill from there. There are a lot of

reasons why, but one of them is that a lot of people see the sport as barbaric because

it causes brain damage. "After the most murderous beating a man ever took in the ring. And there's

the bell." After years of getting hit in the head, many boxers developed dementia and depression

as part of a disease called dementia pugilistica. Nowadays, dementia pugilistica has a new name:

CTE. And it's not just found in boxers, but in increasing numbers of football players,

even causing some people to question the future of the NFL. So people have always known that

playing tackle football causes injuries. Ok i'm going to play football and maybe I'm going

to break my legs, maybe I won't be able to run when I'm 50. Players have known that forever.

But what we didn't know is that tackle football can cause really long-term brain injuries.

There's something a lot less sad about a 50-year-old who can't run versus a 50-year-old who can't

think. "The things we do to one another.... ok ..... uh ... hell I don't know what I'm

saying. I'm just tired and confused right now. That's why I say I can't really -- I

can't say it the way I want to say it." Over the past few years, a number of former players

have committed suicide after battling depression. Afterwards, they gave their brains to science

and upon examination, they showed telltale signs of CTE. Scientists don't yet have a

way of diagnosing CTE for sure, besides doing an autopsy. So apart from the 50 deceased

former players confirmed to have it, they can only suspect that hundreds more are living

with it right now. "9-7-8-4-3-2... 9-7-8......"

For a while the NFL was completely repressing

research. They were telling players that concussions were a relatively safe type of injury to suffer.

But with pressure mounting, the league changed course, settling a class-action suit for $765

million and pouring money into CTE research. The issue hasn't gone away at all. The NFL's

been trying to solve it, and it seems like they're putting genuine efforts into it, but

it just might not be possible. In theory, concussed players are no longer allowed to

enter games. They've moved the kickoff 5 yards down the field so a lot more kickoffs become

touchbacks, so you don't have the high-speed impacts happen when the kicking team is trying

to cover the kick and tackle the player. They've changed the rules in terms of head-to-head

hits. On defense, you can't use your head or your helmet as a weapon. If you're a running

back, you also can't lead with your head to hit other players' heads. Those are the easiest

things to target, they're kind of the lowest-hanging fruit. They can't get rid of concussions entirely

- those rule changes. Some concussions happen on the most random, incidental plays. I mean

you have these huge, fast guys running at high speed so even if you ban specific types

of hits, we're still seeing concussions happen with alarming frequency. There's another problem

- even if they got rid of concussions completely, some of the scientists think that subcuncussive

hits, so even milder type of hits that we might not even notice watching on tv, also

lead to CTE over time. They're still trying to figure that out, but if that were true,

that would basically mean that the game of football as we know it is fundamentally unsafe.

The NFL is more popular than ever. The Superbowl gets over 100 million people, so that's a

third of the country, watching it. And just on a week-to-week basis, you know, more people

watch football than any other sport. It's more popular by an order of magnitude. But

lots of parents are worried about the safety of the sport. A lot of people have come out

and said they wouldn't let their kids play football because of the health risks. "If

I had a son, I would be real leery of him playing." The number of kids under 16 playing

tackle football nationwide seems to be declining. And some state lawmakers have even considered

banning it for kids under 14 entirely. It's unlikely that people are just going to turn

off the TV because they realize the sport is unethical. What's going to kill football,

if it dies, would be parents not letting the next generation of players put on a helmet.

"We've got to find a way in this game to help eliminate that play right there. And I don't

know how you do it."