The men behind those iconic thumbs declared war on a budding genre back in 1980.

Gene Siskel and Roger Ebert were the gold standard of modern film criticism. And for good reason.

Their signature show, “Siskel & Ebert,” made movie reviewing cool. They fought like Itchy and Scratchy at times, but their love of movies always conquered all.

This was before Facebook, Twitter and comments sections, the places where modern movie goers hash it out now. Their passionate debates were must-see TV for film buffs. There’s nothing quite like it on TV today, even if countless YouTube channels attempt similar exchanges on the movies du jour.

They also didn’t overstep their bounds, something that happens with some modern critics. Ever fume over a review that spoils one too many plot points? What about reviewers who slam movies for having themes with which they disagree?

The duo fell into the latter trap over a slasher movie classic.

The year was 1980, and a new horror film hit theaters nationwide. “Friday the 13th” rode the red slasher wave started by John Carpenter’s “Halloween.” The former couldn’t match the latter’s fright quotient, but it snagged a successful formula all the same.

  • Scantily clad women
  • Sex, the R-rated kind
  • Cool kills
  • A killing machine with an intriguing back story

The film made $39 million at U.S. theaters, a bonanza given its tiny budget. Suffice to say it launched endless sequels, a 2009 reboot and fitful talk of more installments.

Siskel and Ebert tried to stop the potential franchise before it got started. The duo spoiled the film’s ending on their television review show.

Why?

It might steer potential ticket buyers away from the film. Bad box office equals no sequels. No sequels means a body blow to the budding genre.

Boy, were they wrong.

FAST FACT: Betsy Palmer snagged $1,000 per day to film “Friday the 13th,” a fee that helped her buy a new car after her old one died.

The pair pushed even further, stepping outside their roles as movie reviewers. According to J.A. Kerswell’s “The Teenage Slasher Movie Book, 2nd Revised and Expanded Edition,” the critics tried to directly shame Palmer for appearing in the film. How?

They implored their viewers to write the actress and, as Kerwell puts it, “share their disapproval.”

Siskel’s print review is even more dramatic, moving beyond his role as audience surrogate. He called director Sean S. Cunningham “one of the most despicable creatures” in the film business. Later in the “review,” Siskel gives the mailing address for Gulf & Western Industries chairman, Charles G. Bludorn. (Paramount Pictures was a subsidiary of the company).

What happened next? Audiences ignored their pleas, making the “Friday the 13th” franchise both a cash cow and iconic monster series.

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Truth be told, it’s one of the lesser horror franchises. The unstoppable Jason Voorhees, though, remains a screen villain for the ages. Just ask Kane Hodder, who built a curious type of fame by playing killer Jason in a number of “Friday” sequels.

Even the very best critics get it wrong sometimes.

Photo by eyecmore on Foter.com / CC BY-SA