In a league steeped with tradition, fans often don't know the answer to one of its widest and most well-known ones. In the NFL, every year, the Dallas Cowboys and Detroit Lions play on Thanksgiving Day. There are three games played on the “NFL's holiday.” And with a near monopoly on sports that day, they produce eye-popping TV ratings. And while there have been three Thanksgiving Day games every year in the NFL since the third game was added in 2006, the Cowboys and Lions have been the stewards of this tradition for far longer. But why do they play on Thanksgiving? How did that tradition start, and why does it continue today? Well, the answer likely won't surprise you. But it hasn't always been smooth sailing since.

Here's a trip down the NFL's memory lane for the Cowboys and Lions.

Why do the Cowboys always play on Thanksgiving?

Dak Prescott, Micah Parsons, Tony Pollard in Cowboys jerseys with turkey dinner in front of them

The Dallas Cowboys are actually the newer tradition on Thanksgiving, dating back to 1966. Then-GM Tex Schramm signed the team up to play on the holiday and drive publicity. And it was a massive success. Over 80,000 fans attended the Cowboys' first Thanksgiving Day game, and every year since, excluding two years in the 1970s, Dallas has hosted a game on Thanksgiving. Because the Cowboys are such a huge draw, there have never really been any serious calls for them to lose their spot hosting a game on the holiday,

This year, the Cowboys will face a Washington Commanders side coming off a game where they self-destructed. All signs point to the Cowboys being favorites and the potential for the first home sweep in a very long time of the Thanksgiving Day NFL slate. Dallas needs to continue their hot run of form in order to stay in touch with the Philadelphia Eagles at the top of the NFC East. Meanwhile, Washington is essentially treading water near the bottom of the NFC. Dallas has to continue to win games against bad teams to avoid ending up in a wild-card spot come playoff time.

Why do the Lions always play on Thanksgiving?

Jared Goff, Dan Campbell, Jahmyr Gibbs in Lions jerseys with turkey dinner in front of them

The Lions have hosted Thanksgiving Day games for much longer than the Dallas Cowboys. Dating all the way back to 1934, the Lions have played 83 times on Thanksgiving since they began their tradition against the Chicago Bears. Owner George A. Richards had the idea that hosting a game during the popular holiday would put butts in seats. And his marketing idea was a wild success. The Thanksgiving Day game in Detroit was immediately popular, pioneered a staple tradition of the NFL, and has been a fixture ever since.

While some of the Lions' woes in the 2010s sparked calls to remove the Lions as host, the NFL, unsurprisingly, has elected to keep this tradition intact. Interestingly, the Lions enter this edition on a losing streak dating back to 2016, extended by a heartbreaking loss to the Buffalo Bills last year. But this is different. They are one of the three best teams in the league, 8-2, and facing a lowly Green Bay Packers team. If now isn't the time to break the streak, who knows when that time will be? And if Detroit wants to cement the turnaround and stay in contention for the top seed in the NFC, they have to take care of business against their long-time rivals.