We rarely get into betting lines here on the NFC North blog, mostly because I have no idea how they work and would be even more exposed in a gambling discussion than I am while talking football. But we've had a development this week that serves as a great starting point to preview the Detroit Lions' game Sunday at the Minnesota Vikings.

As noted on ESPN.com's very own odds and daily line page, the Lions currently are four-point favorites. Longtime NFC North fans know the Lions have lost 13 consecutive games at the Metrodome. Their last victory in Minnesota came on Dec. 14, 1997. All of which spurs the obvious question: How long has it been since the Lions were favored to win a game at the Metrodome?

The short answer: It's been more than 20 years.

I reached out to a few betting experts Tuesday, and none of their computer databases reached back far enough to find one. Johnny Detroit of Pregame.com reported no instances as far back as 1990, and Jay Korengay of the Hilton Sports Book in Las Vegas surmised it was during the mid-1980's. *Update: Further research from Pregame.com indicates the Lions were last favored at Minnesota on Sept. 20, 1981 -- exactly 30 years ago.

The Lions haven't just captured the attention and imagination of fans and fantasy players. The betting community has jumped on them as well. Their 8.5-point line for last Sunday's game against the Kansas City Chiefs was the first time they have been favored by more than a touchdown in a game since 2000, according to covers.com. And the last time they were favored on the road by three or more? A 1999 game against the Chicago Bears, according to Johnny Detroit.

"We've been watching the Lions pretty closely," Kornegay said. "It's very unusual for a team that has struggled for as long as they have to become such a public team so quickly."

Yes, even Las Vegas has Lions Fever.