https://en.m.wikipedia.org/wiki/1969_NFL_Championship_Game

The Minnesota Vikings won the Ed Thorp Memorial Trophy in 1969. The Vikings were the last team to receive the trophy before the NFL–AFL merger.

1969 nfl champions. It is exactly what it says.

The narrative has changed over the years.
At the time. January 1970. Bud Grant initially refused to play kc because of the desparity in practice field conditions accomodations.
Kc housed & practiced at tulane stadium. And college dorms.
Vikings housed in a high school gym an hour away from tulane. Practiced on a high school field full of chuck holes.j

The nfl turned the screws tight on viking ownership. The vikings were forced to play after a week where instead if onfield practice. They held walk throughs on the high school black top.

If it looked, on the field on game day. Like the vikings were outclassed & ill prepared. Its because they were.