Not that anyone expected huge numbers from Reese Witherspoon's new comedy "Hot Pursuit," especially with "Avengers: Age of Ultron" still sucking all the oxygen out of the multiplex. Even so, predictions ranged from $15 to $20 million for the buddy-comedy's Mother's Day weekend debut. Instead, it earned just an estimated $13.3 million.

The film's lackluster opening reinforces a number of lessons about the way the box office works now, some of which defy conventional wisdom. For instance:

Counterprogramming Doesn't Work. We've seen that over and over again this spring, especially with male-oriented action movies that have opened weakly against female-oriented smashes like "Fifty Shades of Grey" and "Cinderella." The opposite appears to be true as well for women-targeted movies opening against testosterone-heavy action blockbusters, especially when the spectacle you're programming against isn't entirely male-dominated but makes some effort to appeal to women as well, as the "Avengers" and "Fast and Furious" franchises do. Just because women ticketbuyers might not feel served by "Ultron" or "Furious 7" doesn't mean they're going to come out to the theater for a female buddy comedy instead.

Execution Matters. "Hot Pursuit" might have gotten away with being a pale photocopy of "The Heat," but that film had original characters, brazenly adult (R-rated) humor, and two proven box-office draws in the lead roles. By all accounts, "Hot Pursuit" has none of those things. Word-of-mouth on the movie is very poor, judging by the C+ it earned from CinemaScore. Critics almost universally panned the movie as well, which matters when you're targeting an older, female audience that actually cares about reviews. And speaking of that audience...

Don't Count on the Holiday Crowd. Just because it's Mother's Day weekend doesn't mean your mom wants to see a buddy-cop comedy that has two well-liked actresses in the lead roles. After all, the third place movie this weekend was "Modern Family," which is she going to choose?

Sofia Vergara Is Not a Movie Star. Not yet, anyway. The "Modern Family" ensemble member may be the highest-paid actress on TV, but she hasn't been able to translate that level of small-screen notoriety into box office appeal. You can be gorgeous, funny, and talented and still be best-known to film audiences for playing third banana to a bunch of Smurfs. But then...

Star Power Doesn't Last. Witherspoon was a big box office draw as recently as seven years ago (when her comedy "Four Christmases" grossed $120.1 million). Lately, however, not so much. "Hot Pursuit" does mark her strongest debut in three years, since "This Means War" opened with $17.4 million. But the days of "Legally Blonde" and "Sweet Home Alabama" are far behind her.

She's in good company, at least, especially this week. No one's a better example of a faded box office draw than Arnold Schwarzenegger. Once upon a time, a zombie movie starring Ah-nuld would have opened wide and with tens of millions of dollars, but this weekend, his "Maggie" opened on just 79 screens with an estimated take of $131,000. ("The SpongeBob Movie: Sponge Out of Water," now in its fourth month of release, did better than that this weekend, with an estimated $155,000.) Granted, it's being marketed as more of an indie drama about a father caring for his ailing daughter than a horror genre piece, but still, it's Arnold Schwarzenegger and zombies.

Then there's Jack Black's new comedy, "The D Train." Also an indie film, but one released on 1,009 screens. It was widely expected to make $2 million, but it earned just an estimated $469,000. That's just $465 per screen, about a fourth of what "Maggie" earned per showing.

All that is to say that any film that relies on star power alone to sell tickets is in deep trouble, especially if the star is past his or her box office prime.

One more thing: There's been a lot of talk about institutional sexism in Hollywood over the past couple weeks, especially with all the backlash over "Ultron" and its patronizing Black Widow storyline, Sony's drama over whether to pay Jennifer Lawrence her $20 million asking price to star in space-romance "Passengers," and the reluctance of Sony and Marvel (as outlined in a leaked e-mail) to make any superheroine movies because the only three major examples of the past 31 years ("Supergirl," "Catwoman," and "Elektra") have all flopped. A lot of industry observers have found that e-mail assessment especially unfair. After all, there have been several even bigger male superhero flops (most notoriously, "Green Lantern"), and that hasn't stopped anyone from greenlighting male spandex action spectacles. But the superheroine kerfuffle is seen as a symptom of a larger problem, which is that Hollywood is generally reluctant to make movies with prominent roles for women or that are targeted toward women ticketbuyers. It's a self-fulfilling prophecy: The industry feels such movies don't make money, so it doesn't make them, but because the studios won't make them, there are few counterexamples of successful female-driven movies. The ones that do get made and that do succeed, like "Fifty Shades" or "Cinderella" are considered flukes, rather than evidence of a hungry marketplace gobbling up what little is offered.

Witherspoon has tried to combat this by becoming a producer and creating opportunities for herself, including her drama "Wild," which earned her an Oscar nomination last winter, and now "Hot Pursuit." Unfortunately, the lackluster response to her new movie means it could be a while before a studio takes a chance on a Witherspoon production again, since women are not yet allowed to fail and keep working in Hollywood the way men are.

And that seems to be the real test of whether you've achieved lasting career success in the industry: not whether you make hit after hit, but whether you get to flop and still keep getting opportunities. Leonardo DiCaprio is allowed the occasional misfire, as are Will Smith and Tom Cruise and Sandra Bullock. When Witherspoon, Lawrence, Scarlett Johansson, Kristen Stewart, and other actresses get to make expensive stumbles like "Hot Pursuit" and move on to the next studio project, then we'll know that Hollywood has reached some measure of gender parity.