Someone somewhere in the mid- to late 1980s had the brilliant idea that Sweden’s Dolph Lundgren — the man who portrayed Captain Ivan Drago in “Rocky IV” and He-Man in “Masters of the Universe” — would be the perfect lead for the big screen debut of Marvel Comics character Frank Castle, aka The Punisher.

Someone else decided to gamble on casting Michael Keaton of “Beetlejuice” and “Mr. Mom” fame as Batman.

Lundgren — stiff, awkward, unintelligible and sans skull — flopped.

Keaton — an actor who could, well, act — brought comics its biggest silver screen hit since “Superman.”

To be fair, Lundgren’s “Punisher” suffered from a poor script and even worse direction. Keaton had Tim Burton on his side.

But the key to success for “Batman” — its impeccable casting of Keaton, Kim Basinger, Jack Palance and Jack Nicholson — was the precursor for a trend that has vaulted today’s comic book films to unprecedented heights.

Does “X-Men” break the $100 million mark without Hugh Jackman and Patrick Stewart?

Does “Batman Begins” strike a nerve with the audience without the brooding Christian Bale?

Is “Iron Man” a hit without Robert Downey Jr.?

Other actors could have filled these roles, but it is the casting of GREAT actors that has been the difference between box office failure and success.

And the trend continues. Last week, Marvel Studios announced Sir Anthony Hopkins would be joining the cast of “Thor” as Thor’s father, the Norse god Odin. Hopkins, who has starred in more than 100 films, is an Oscar winner. Talk about upping the ante.

Natalie Portman was already cast as Thor’s love interest. And Kenneth Branagh, a talented actor in his own right, will direct. With Chris Hemsworth, who portrayed Kirk’s father in this summer’s “Star Trek” in place as the thunder god, all the pieces seem to be in place for another box office hit.

Not to be out done, Warner Bros., purveyor of all things DC, has loaded its next project, “Green Latern,” with big names. This summer’s box office sweetheart Ryan Reynolds will star as Green Latern Hal Jordan, while character actor Jackie Earley Haley is reportedly cast as Jordan’s teacher and eventual nemesis Sinestro.

Now, this is where a word of caution must be conveyed to Hollywood.

Studios cannot be content with simply casting great actors. True, big names will bring people to the theaters, generally translating to box-office success. But casting is just 50 percent of equation.