Are the Vikings the worst 6-0 team of all time? Where Minnesota stacks up in history

Let's start with this: Only good teams go undefeated. It's one thing to win a game or two, but if you're starting 6-0, you're a good team. The Minnesota Vikings are undoubtedly a good team. But not all 6-0 teams are created equal. The 1999 Rams beat their first six opponents by an average of 25.7 points. That is dominance. Compare that with this year's Vikings, who have won four of their six games by less than a touchdown. So, are the Vikings the "worst" 6-0 team in NFL history?