After a September dominated by "IT," we were suddenly supposed to get a close three-way race at the box office this weekend. Didn't quite happen.

While "IT was expected to fall to $30 million -- a still-impressive figure for a movie in its third weekend of release -- the horror hit was supposed to face close competition from two new wide-release sequels to popular franchises. Predictions for "The LEGO Ninjago Movie" were all over the map, but analysts believed both movies would open in the 30s and maybe even the 40s.

As it turns out, predictions for "IT" were right on the money, since it came in exactly at $30.0 million according to estimates. But "Kingsman" dethroned it with an estimated $39.0 million. While "Ninjago" debuted in third place, it fell well below expectations with just an estimated $21.3 million.

Why did "Kingsman" so easily take the crown while "Ninjago" bricked? Some experts will be arguing that the lopsided victory demonstrates how much "IT" has rewritten the rules for what to expect from the September box office, but really, it's just a matter of following the old rules, which "Kingsman" did and its competition didn't. Among the factors that mattered:

1. Timing

Exhibitors may have thought that, after a summer of tumbleweeds and crickets at the multiplex, the enormous success of "IT" got moviegoers back into the habit of going to the theaters no matter what's playing. Not so; audiences are still picky and careful with their money. For instance, not too many were going to go see another horror movie while "IT" was still playing, which is one reason why "Friend Request," this weekend's third new wide release, disappointed with a seventh-place premiere and a take estimated at just $2.4 million (although its budget was only $9.9 million).

Meanwhile, "NInjago" may have had the family marketplace to itself, coming out two months after the last big family hit ("The LEGO Batman Movie," and it's not clear that there was demand for another film from the brick-toy franchise so soon after the last one.

"Kingsman"' had its own timing issues, yet its opening is still impressive for early fall. American Made," for which some action fans may be saving their money. In fact, "Kingsman" now boasts the fifth-biggest September debut of all time. Manners definitely make the man (and the box office gold).

2. Age

Unlike the first two "LEGO" films, "Ninjago" has little appeal for adults. Not only did the first two spoof pop culture franchises and characters that were familiar to grown-ups, but they also got great reviews. "Ninjago," however, draws on a recent kiddie TV series that few adults know, and its reviews were mixed (just 53 percent fresh at Rotten Tomatoes). As a result, while moviegoers over 18 made up 59 percent of "The LEGO Movie" audience and 62 percent of the "LEGO Batman" crowd, they made up only about half of the "Ninjago" viewers.

"Ninjago" and three-week-old romantic comedy "Brad's Status," which expanded into 453 venues and landed at No. 12 with an estimated $1.0 million.)

Even so, the R rating helped "Kingsman" while hurting "Friend Request." For "Kingsman" fans, the rating proves that the movie isn't skimping on the sex and violence that distinguish the series from more decorous and discreet spy franchises (like the coy but PG-13 James Bond movies). "Friend Request," however, might have benefited from a PG-13 in order to attract the teens who might have embraced the movie's social-media-driven plot.

3. Star Power

Actually, we're not sure if this matters much at all anymore -- but we're including it anyway. Horror movies don't need stars to succeed (as "IT" has proved in spades), and it's not clear that the star-studded "Kingsman" cast was an asset. Lead Logan Lucky."

And the star-heavy voice cast of "Ninjago" might actually have hurt the film. After all, young fans are accustomed to the voice players from the TV show. Many were alienated by hearing their beloved characters voiced by strange new actors on the big screen.

4. Execution

That's really the most important thing -- not necessarily being good enough to please critics (indeed, all three of the new wide releases earned "rotten" scores at RT), but rather, delivering what audiences want. That's the difference between a franchise that still feels fresh, as "Kingsman" does to its fans, and one that doesn't. After three installments, the diminishing returns for the "LEGO" movies is apparent. The first opened with $69 million, the second with $53 million.

After a summer full of family-movie sequels that underperformed -- "The Nut Job 2: Nutty by Nature" -- it's clear that family franchise installments are no longer automatic hits. The parents who buy the tickets are more discerning, and they're not just going to shell out for anything animated. Parents can tell when a sequel is less a story that needed to be told than a cynical cash grab. Judging by "Ninjago," kids can tell, too. That's a lesson that franchises for teens and grown-ups should heed as well.