Longtime sports broadcaster Jim Nantz is known for many things, but perhaps his most recognizable line and assignment comes from his work with The Masters — the major golf tournament he refers to as "a tradition unlike any other."

In one of Nantz's other major assignments for CBS, however — working as the lead play-by-play voice for NFL along with analyst Tony Romo — there has been far more evolution than tradition over the years.

One of the more recent wrinkles to the NFL broadcast schedule happened in 2014, when CBS and Fox were given the ability to "cross-flex" games into the coveted 3:25 p.m. national slot, which the networks split during the season.

Simply put, cross-flexing allowed the networks to scoop up coveted games for the national slot regardless of whether they were AFC or NFC matchups.

Previously, CBS broadcast all the Sunday AFC games (and games featuring one team from each conference where the AFC team was on the road) while Fox had all the Sunday games between NFC teams and cross-conference matchups where the NFC team was on the road).

It was a little confusing, particularly to those of us who remember a simpler slate of NFL games (more on that in a minute), but there was a standard that you could quickly remember even if you forgot about it temporarily while searching for a game on Sunday.

Cross-flexing, though, means that two NFC teams might wind up playing on CBS. It's happening more than ever this year, per Sports Video Group. It happened last week when the national matchup between two NFC foes, the Cowboys and Seahawks, was on CBS.

And more importantly to you, it is happening again this Sunday when the Vikings play at Chicago at 3:25 p.m. on CBS, with Nantz and Romo on the call.

Why cross-flex in the first place? Doesn't it just seem confusing for an audience accustomed to having NFC games on Fox to have to search for them, however brief the search is?

Well, the Washington Post tackled the question in good detail last season when a Dallas/Washington game was on CBS. Per their story:

To understand how "cross-flexing" works, you have to start with the built-in imbalance between the NFC and AFC. Fox and CBS broadcast the same number of games annually, but their packages are not created equal. The NFC features prominent teams in big markets such as the Cowboys, Chicago Bears and San Francisco 49ers, giving it an inherent ratings advantage. That is reflected in the price of the deals: CBS pays $1 billion per year for the AFC, while Fox pays $1.1 billion for the NFC.

This isn't the first time the Vikings were cross-flexed. In fact, a Vikings/Bears game from 2014, the first year of cross-flexing, was shipped to CBS. (The Vikings lost 21-13 at Chicago, which unfortunately for Minnesota has also been a tradition unlike any other. Minnesota is just 3-15 in road games against the Bears since 2001, though two of the wins came in 2015 and 2017 during division-winning seasons under Mike Zimmer).

It's also a reminder that NFC games on CBS used to be the norm until 1994, when Fox took over the conference from CBS after outbidding the network for rights. CBS was out of the NFL game for four years until 1998, when it outbid NBC and became the network airing AFC games.

As someone who has watched the NFL on TV for almost 40 years, the evolution is amazing. The addition of a regular Thursday night game … a second Monday night game on opening week … a third Thanksgiving game … flexed games … they all create a seeming wall of football.

The Vikings will appear in five different networks this year (Fox, CBS, NBC, ESPN and NFL Network) and one streaming service (Amazon Prime Video). Some teams will play on four different days throughout the season (Thursday, Saturday, Sunday and Monday, with six teams playing on Saturday, Dec. 21 TBA because they will be flexed into that date).

One of my clearest memories of watching football as a small kid was straining to stay awake for the halftime highlights from all the Sunday games during Monday Night Football (8 p.m. kickoff on ABC back then).

Now I watch highlights in real time on my phone, tablet, laptop — or on my TV, as long as I can figure out what channel the game I want to watch is on.