In a lengthy interview earlier this offseason, San Diego general manager A.J. Smith repeatedly pointed to his team’s horrendous third-down defense as the root problem in a playoff-less season.

Fixing that issue was Smith’s primary goal for 2012.

The Chargers were last in the NFL on third-down defense last season. If you can’t get your defense off the field, it’s difficult to win. The most pressing task for new defensive coordinator John Pagano is fixing the problem and Smith’s moves on defense this offseason were made with third-down success in mind.

Just how bad was the Chargers’ defense on third down in 2011? I enlisted the help of stat guru Jason Vida of ESPN Stats & Information. His findings were fascinating.

San Diego’s defense was historically bad on third down last season.

According to Vida, the Chargers allowed opponents to convert 49.2 percent of third downs in 2011. It was the highest total of any NFL team since the 1995 Cleveland Browns.

It was San Diego’s worst third-down percentage since 1975 when it allowed opponents to convert 50.7 percent on third downs.

The 2011 Chargers were especially bad on third-and-short situations. On third downs where opponents needed 1-5 yards to convert, opponents converted 65.6 percent of the time, which was the worst mark in the league. From six yards and beyond, opponents converted 34.7 percent of the time on third down, which was 29th in the NFL.

Many thanks to Vida for his help on this post.