WASHINGTON (THE WASHINGTON POST) - There's no shortage of reasons Avengers: Infinity War notched an insane record-breaking opening in the United States this past weekend.
The US$250 million total - just ahead of Star Wars: The Force Awakens in 2015 - can be chalked up to the sheer depth of its character bench, the deft commercial touch of its directors and the fact that it felt like a culmination of the Marvel Cinematic Universe - almost 10 years to the day after Iron Man (2008) hit theaters and started it all.
Yet one factor may be sneakily making its presence felt: the success of Black Panther's opening just 10 weeks before. After all, that movie was a blockbuster - it's now the third-highest-grossing movie of all time in the United States. That should make people a little more primed to see another movie set in the same universe with the same characters, shouldn't it?
This seems like a nice - but entirely unprovable - theory. Moviegoing motivations are hard to divine. And they're really hard to divine on a mass scale like Infinity War. Yet there's a data-driven way to demonstrate that this might be more than speculation - simply put, by testing whether a Marvel movie that was quickly followed by another had an effect on its successor in a way movies more spaced apart did not.
Thankfully, there's a large data set after 10 years of MCU movies. Of the 18 that have come since Iron Man, exactly half were released within five months of their predecessor; the other half came out beyond that period, sometimes much beyond it.
Looking at the opening weekend for these movies, a striking pattern emerges: the swing between films that came out one after another was smaller than those that didn't. Much, much smaller. Releases that come close together, it turns out, affect one another, whether for good or for ill.
The average swing between movies that came out within five months (again, in either a positive or negative direction) was 24 percent, according to data analysed by The Washington Post.
The average swing among the movies that were more spaced out? A whopping 101 percent.
In fact, nearly half of those films that came out within five months of one another had an opening-weekend variance of no more than 11 percent. Two sets of movies - Thor and Captain America, and Captain America: The First Avenger and Guardians Of The Galaxy - had an opening-weekend variance of 0 percent. They opened to exactly the same amount as one another.
Again, this correlation holds both in the case of both success and failure. A hit like Thor: Ragnarok retained all (and even gained a few more) of its audience members from Spider-Man: Homecoming a few months before (an uptick of 5 percent, to US$123 million). An underperformer like Captain America: The First Avenger, on the other hand, stayed in the same doldrums as Thor two months earlier - both grossed US$65 million.
Why this happens isn't hard to figure out. The Marvel movies have a distinct look and feel, which makes for strong brand associations. If two movies come out close to one another, one will affect the other. After a certain point, we forget about the previous movie and the effect dissipates.
Which takes us back to Infinity War. The superhero film, coming 10 weeks after Black Panther, also had a similar opening-weekend as its predecessor - a 24 per cent swing. (To Disney-Marvel's satisfaction, this was in the upward direction.)
Had Infinity War waited a longer, six or eight or 10 months, the prospects for it to follow in Panther's footsteps, statistically speaking, would have gotten much lower.
Infinity War had another advantage coming on the heels of Black Panther: It featured the latter's lead character in a significant (i.e., credited) role. That link is harder to test, because Marvel hasn't been releasing movies in immediate succession with the same characters very often.
But when they do, there has been a correlation, too. The last time they did it, with Iron Man 3 following The Avengers five years ago, the movie dropped 11 percent from Avengers' massive opening weekend.
From a strategic standpoint, Disney-Marvel can't really do much to game-plan any of this, since the effect occurs in both a positive and negative direction. But the logic does say that if the studio has a hit, it should release another movie soon after.
In fact Infinity War, Panther and Thor came out in quicker succession than any three movies in MCU history. Some might say that's too much too quickly - the fear among a number of Hollywood analysts had been of a Marvel overload. But as last weekend's box office suggests, a surprising truth currently exists about the studio's movies: There's no such thing as too soon.