TBM’s interactive tool measures whether critics affect box-office receipts.

Nobody stands in the way of Watchmen’s box-office domination. There is not a single other film opening in wide release this weekend. Instead, all the studios have cleared their calendars to allow Watchmen to steamroll the leftovers. And considering its stiffest competition is a three-week-old movie about a badly behaved grandmother, it should make considerable bank this weekend. Analysts are predicting a $50 million to $70 million haul.

That prediction comes despite a slate of middling reviews. Critics have alternated between gushing praise and odiferous hate for the film, yet none of that has managed to puncture the dollar-hype. When it comes to blockbuster films, critics’ reviews are perceived to be toothless. Hollywood places a tremendous amount of pressure on the opening weekend’s performance, which means that critics are but gadflies on a studio’s cash cow. They insure themselves against critical wrath by hyping the films to the brink of overexposure. Watchmen’s ad campaign has been overpowering—Rorschach’s face seems to follow us from bookstore kiosks to billboards to viral Web sites. A.O. Scott doesn’t stand a chance against masked psychopaths. So let’s agree that Watchmen will coax tens of millions out of recession-addled Americans—especially considering this year’s 17.5 percent spike in ticket sales.

But then what? Blockbusters are still in theaters long after the first weekend. And that’s where, ironically, the critical reaction can tell us quite a bit. We created a tool to surmise whether Watchmen will be a flash in the pan or have major staying power. Our number-crunching has pumped out the following calculation:

In its first weekend, Watchmen will bring in 32.7 percent of its total box-office gross. That’s about average for action blockbusters and only 1 point below the first-weekend take of 300 (director Zack Snyder’s other film).

How’d we get to that number? The Big Money and Slate delved into box-office archives to collect data on five years worth of blockbusters. Then we culled their critical reaction from Metacritic and compared the data. We defined a blockbuster as a movie—any genre—that made more than $75 million and opened on more than 2,500 screens. Those thresholds cast a wide net and made sure we grabbed the blockbusters that flopped as well as the ones that set records—161 movies in all.

We’re out to judge whether critical response is predictive of a film’s take after its opening weekend. So we’ve calculated the percentage that a film’s opening weekend contributes to its total box-office gross. Thus, the smaller that percentage, the more evenly distributed its box-office revenues over time. Given how front-loaded box-office returns are these days, the difference between top-heavy and more evenly distributed movies translates roughly into the difference between a fad and a movie that defines the cinematic season. You can see the results of our investigation on our homemade tool below: