Minnesota fans who are a bit older remember the glory years of the Purple People Eaters. Even those that do not must understand how good the defense was to even have a nickname. In the modern era of the NFL few teams did. In the 1970s there was the "53" No Name Defense of Miami and the Steel Curtain of Pittsburgh. In the 1980s the 46 blitzing Monsters of the Midway won Chicago a Super Bowl. The Baltimore Ravens had an impressive run resulting in a Super Bowl win in the 2000 NFL season. In that Ray Lewis led season, Baltimore surrendered 23 points in four playoff wins.
But Minnesota might have had the best defense of all-time.
In 1969, the Vikings defense surrendered 133 points in 14 games. Only one opponent scored twenty points or more. Minnesota's defense was first overall in points allowed. They would repeat that feat in 1970 and 1971. Minnesota gave up 143 and 139 points the next two seasons. In fact, Minnesota would go 41 straight games giving up less than 24 points from 1969 to 1971.
After a slip in 1972, Minnesota's defense finished 2nd, 3rd, 3rd, and 2nd the next four years. During those four years (1973-76) Minnesota went to three Super Bowls. The defense was so opportunistic that Minnesota's offense scored in the top ten each of those years.
Of course no Super Bowl wins.
Since 1976 Minnesota has had only one defense that finished in the top four in the NFL. In 1988 they finished 2nd overall, having improved from 1986 and their 5th place finish. That defense helped Minnesota make it to the Conference Championship in 1987, falling short to Washington. The 1998 Vikings were so good offensively that the '98 defense finished 6th overall. That team lost in OT in the home NFC Conference Championship to Atlanta.
That is it.
Presently the 2014 Vikings defense is 12th overall in points surrendered per game. They have allowed 47 points in the last three games, or 15.6 points per game. The fact that their opponents were a wounded Lions team, and two lesser offenses in Buffalo and Tampa Bay should not deny the idea that Minnesota is starting to improve defensively.