The decline of QB sacks in the NFL

Deacon Jones (bottom) made life difficult for Johnny Unitas and other QBs of his era. Walter Iooss Jr./SI

If you watched the Vikings' two wins over the Packers this season, specifically Minnesota defensive end Jared Allen introducing himself to Green Bay quarterback Aaron Rodgers 7.5 times, you might think the sack is alive and well in the NFL.

You'd be wrong.

There have been just 521 sacks in 7,630 pass attempts so far this year, among the lowest rates of sack-success in NFL history, and a far cry from the days when the likes of Deacon Jones dominated overmatched offensive tackles and made life a living hell for quarterbacks.

In fact, this is a story best told through the legend of Jones, the sack specialist extraordinaire whose brutal, head-slapping, QB-pummeling style of football lives on today only in the murky netherworld of myth and in the flickering images of grainy old black & white game film.

The Hall of Fame defensive end was the greatest player of the mighty "Fearsome Foursome" fielded by the L.A. Rams in the 1960s (with Merlin Olsen, Rosey Grier and Lamar Lundy). Jones is also the very man credited with coining "sack" as the term for pillaging the passer.

The exploits of the sack specialists, however, are not well documented. In fact, most sacks are lost to history. They weren't even an "official" stat until 1982. So we have no way to measure the great individual pass rushers, Jones high among them, of the 1960s and 1970s, the golden age of the sack specialist.

Jones essentially lived in statistical anonymity. Here he was, routinely breaching the city walls and sacking the emperors of the sport, but with virtually no credit to go with it. We can assume it was some of that discontent with the anonymity of his position that caused Jones to coin the perfect phrase for his craft.

But, while we have no way of measuring Jones' individual greatness, we do have team sack stats from the 1960s, thanks to resources such as ProFootballReference, NFL.com and the ESPN Pro Football Encyclopedia.

And, thanks to these resources, we now know this: the game that Jones lorded over in the 1960s no longer exists. The art of the sack is quickly being legislated from the game in the NFL's blind rush to put skirts on its quarterbacks and produce pinball-sized scores.

1964: The Year of the Sack

The 1964 season was notable for many reasons, namely for the AFL-NFL wars that were rapidly reaching a fever pitch. But the stat geeks among us are interested to discover that the 1964 season was the first in which Deacon Jones reached the Pro Bowl and, perhaps not coincidentally, it was also the height of the sack: NFL quarterbacks were pummeled in the backfield on 11 percent of pass attempts in 1964, the highest rate in modern history (1960-present).

But in today's game, the sack rate is nearly half what it was in 1964:

In 2008, quarterbacks were nailed in the backfield on just 6.2 percent of pass attempts -- the second lowest rate in the history of the game.

In 2007, it was statistically similar: quarterbacks were dropped on just 6.5 percent of pass attempts.

Here in 2009, 6.8 percent of pass attempts have resulted in sacks.

Quarterbacks today, in other words, don't face the kind of pressure that they did in the 1960s. Here's a look at the 10 toughest seasons for quarterbacks, based on sack percentage:

Seven of the 10 sack-leading seasons took place in the 1960s. The 1976 and 1977 seasons, meanwhile, marked the absolute depths of the Dead Ball Era, the seasons so dominated by defenses that the NFL was forced to institute wholesale rules changes before the 1978 season to save the sport from returning to its Stone Age 1930s scoring levels.

But in the effort to open up offenses, the NFL started to close the door on defenses. As a result, sacks are far less common today than they were in the past. Here's a look at the seasons with the lowest rate of sacks. Most of them have taken place this decade and all have come within the past two decades.

Generally speaking, sacks are about 50 percent less common today (roughly 6.5 percent of dropbacks) than they were in the 1960s (9.75 percent of dropbacks).

The decline in sacks coincides quite nicely with the rise of video-game style passing stats. The highest cumulative, league-wide passer ratings have all come this decade:

• 2009 (to date) - 83.9

• 2008 - 83.2

• 2004 - 82.8

• 2007 - 80.9

• 2006 - 80.4

• 2002 - 80.4

With the exception of 2004, the greatest passing seasons were the seasons with the lowest sack rates. Even 2004, the third-best season for passers in history, wasn't too far off the list (7.3% sack rate, 13th lowest on record).