For the last half-century, Sundays have been dominated by the NFL. It’s the one day of the week where almost every sports fan gathers around a TV for a day of relaxation, food ingestion and hard-fought American football. For the most part the NFL has remained largely similar during this time span; however fast forward 20 years from now and the NFL as we know it may be completely changed.

So what could possibly change one of America’s most endearing past-times? That answer lies not in the people watching the games, but with the players themselves. Specifically, their brains.

The Department of Veterans Affairs and Boston University have been working closely together on examining the dead bodies of former NFL players, as well as athletes who only played football in high school or college. They have found that out of all of the players tested, 79 percent of them (131 out of 165) had Chronic Traumatic Encephalopathy (CTE), a brain disease that can lead to depression, memory loss and insanity. Of these 165 players, 91 played in the NFL, of which a staggering 96 percent were discovered to have CTE. However, the cause of this brain degeneration isn’t exactly what it seems.

When you think of scenarios in football where it seems that players could become susceptible to brain trauma, your mind probably conjures up images of Jadeveon Clowney and other huge linebackers and defensive players absolutely trucking some poor wide receiver or quarterback. While these instances are the most likely to cause concussions, they aren’t in fact what causes CTE and other long-term brain disorders.

CTE is actually believed to be caused by repeated minor instances of contact to the head, something any football player who plays long enough is bound to face. Just think of all of the tackles, hitting and blocking that goes on game in and game out. Although in that exact moment no damage is done, the long term effects, like CTE, could prove to be life-threatening as they were to a few famous NFL players.

Junior Seau and Dave Duerson both played in the NFL for over a decade, and earned multiple Pro Bowl selections and team honors in the process. In 2011, Duerson committed suicide by shooting himself in the chest; however, he left a note before he died asking for his brain to be sent to a lab for research. Seau committed suicide in 2012, and after his death, his brain was also sent to a lab for research. In both cases, CTE was found to have led them to suicide.

On Dec. 25, “Concussion” will be released, a film starring Will Smith. He plays the role of Bennet Omalu, the neurosurgeon who discovered CTE in the brain of former Pittsburgh Steelers center Mike Webster in 2002. Although the film does represent an era before all of the rules regarding reckless tackling and blind hits were made, it undoubtedly will serve as a wake-up call for anyone who has not yet heard of the NFL’s ongoing problem with brain damage.

These scientific findings are a harsh reality for the NFL. Although the league has done its best over the past few years by installing new rules regarding return times of players with concussions and restrictions on how players can tackle, it won’t ever be enough. The NFL can do it’s best to take away the huge, jaw-dropping tackles it has become so well known for, but as science has recently proven with CTE, that’s not the issue. The issue is the relentless tackling and, frankly, the fearlessness players exhibit on the field. When they are under the protection of their helmets and pads, they feel like they have no limits and can tackle however they want. If the NFL truly does care about its players and wants to increase its safety, then a complete overhaul of the game-style is going to have to take place.

If this sounds extreme, just take a look at rugby, a sport very similar to football in many aspects (such as tackling), but different in one key way: no pads. You’d think that by having no pads, players would automatically become more at-risk to dangerous injuries and head trauma, but in actuality the exact opposite is true.

By taking away the player’s armor, you essentially take away his sense of fearlessness and invincibility, and thus decrease the amount of insane tackles. Players have to learn to tackle with their whole body, and not just slam their opponents straight into the ground. If the NFL ever wants to avoid the nasty press coverage and medical opponents it has been so hastily gaining, then perhaps it should take a lesson from rugby and change the way the game is played.