Tatort” (Crime Scene) Germany’s top-rated detective series, celebrated its 40th anniversary last week with a surge of Teuton media attention that left its creator struggling to explain its improbably long run on pubcaster ARD.

“Tatort,” which has had 102 detectives in 781 episodes since its debut on Nov. 29, 1970, has drawn an average of 8.5 million viewers this season, making it Germany’s most-watched series.

In fact, the ratings in 2010 have been the best for the show since 1995.

“Tatort” rotates around Germany’s 16 federal states each Sunday evening with different sets of police detectives in those states spending 90 minutes tracking criminals.

“We were actually quite relieved that we made it through to the end of the first season,” says Gunther Witte, who created “Tatort” and admits he never dreamed it would last 40 years.

He spread the series around the country with episodes in different cities with different detectives for one reason: to share the production costs among ARD’s regional webs including WDR, HR, BR and NDR.

“The most important question at the start was: ‘How are we going to finance this?’ We opted to get all the regional broadcasters involved,” he says.

“Tatort” has not only been ARD’s crown jewel for four decades; it’s also been a showcase for Germany’s top talent, with Wolfgang Petersen directing a number of episodes and thesp Christoph Waltz making an appearance.

Ulrich Tukur and Martina Gedeck — of “The Lives of Others” fame — teamed up for the 40th anni show on Nov. 28, watched by 8.7 million for a 23.6 market share.

“The series has always reflected its era,” Tukur says. “There’s been some trash in it over the years but a lot of gems. Some films were actually good enough to get a cinema release.”

The first episode of “Tatort” was called “Taxi nach Leipzig” (Taxi to Leipzig) and got a 61 market share back in the days when Germany had just three national webs.

On Jan. 20, 1974, it pulled in a 76 share and an estimated aud of over 30 million.

The most famous episode, “Reifezeugnis,” starring a young Nastassja Kinski as a schoolgirl having an affair with her teacher, got a 67 share on March 27, 1977.

Many of these “Tatort” classics have been repeated in recent weeks to stellar ratings on ARD member webs. They offer riveting snapshots of the fashions, mores, language and political situations as well as cultural disputes of their respective eras.

One example of this is that there are now as many women detectives as men — NDR’s Maria Furtwaengler regularly pulls in top ratings for her three appearances each year.

But while times change, the basic formula has remained the same since the start. The focus is on the detectives, and often their own foibles, and the stories are uniquely German with almost no action and rarely even a shot fired. The cops rely on their brains or the blunders of the criminals to get their man.

“What’s most astonishing about ‘Tatort’ is that it is in essence a TV style from yesteryear,” wrote TV critic Tilmann P. Gangloff in the Koelner Stadt-Anzeiger newspaper. “Yet no TV series manages to re-invent itself as much as ‘Tatort.’ So each film is a perfect seismograph for everything that changes in Germany, in both TV production and in society at large.”