After the biggest summer on record, Hollywood dropped the ball in the fall. Through Oct. 21, domestic box office is 6% behind last year, with the lowest total ($785.7 million) since 2001, according to Rentrak.

The main culprit: The studios’ big films failed to score. DreamWorks’ “The Heartbreak Kid,” Universal’s “Elizabeth: The Golden Age” and DreamWorks’ “Things We Lost in the Fire” are among the titles that underperformed.

But another key factor is the corporate takeover of the niche world. For years, rival studios have dreamed of emulating the Fox Searchlight model, with an arm that would release “quality” films. But this fall, many hierarchs have supervised the launches of these pics, trying to apply mainstream strategies to niche films.

The studios’ gambles:

  • The films are going wide too soon. Pics like “Things We Lost in the Fire” and “Michael Clayton” were treated like star vehicles, rather than specialty films.

  • They’re releasing too many similar films in too short a corridor. During summer, studios carefully study rivals’ releases and avoid conflicts. This fall, audiences were given little range, with crime dramas (“We Own the Night,” “Eastern Promises,” “Gone Baby Gone,” “The Brave One”), family dramas (“Things We Lost in the Fire,” “Reservation Road”), Iraq-themed dramas (“In the Valley of Elah,” “Rendition”) and miscellaneous dramas (“Sleuth,” “The Jane Austen Book Club,” “The Assassination of Jesse James by the Coward Robert Ford”).

  • The majors are backloading their releases. After pulling out the big guns during summer, they ghetto-ized September and October, saving titles like “Bee Movie” and “American Gangster” for early November, and other biggies for the holiday period.

  • By emulating the summer strategy of launching a new title every few weeks, studio congloms ignore the fact that specialty pics need time to build word of mouth. So films that are performing fine (“Into the Wild,” “Lars and the Real Girl,” for example) have to fight for screens as a new crop of films opens every week.

Whenever B.O. dips, studio execs accept little blame: The problem, they say, is not the quality of the films, it’s the glut of R-rated dramas. But there aren’t that many more this year than in previous years. In the past two months, Hollywood debuted 110 movies, up just two from last year.

In terms of profits, most studio execs contend their fall pics were relatively inexpensive to produce — hence, they aren’t expecting to take too much of a hit. But many in Hollywood believe these films had potential for higher grosses.

“We need a diversity of product throughout the year,” National Assn. of Theater prexy John Fithian says. “Nobody wants to be daring in their release schedules.”

Or, as one studio exec put it, “we’re bludgeoning our audience.”

Specifically, there’s been a lack of family titles, comedy and actioners — or at least ones that work.

For the September-October period, the only film that has passed $70 million is Disney’s comedy “The Game Plan,” which had grossed $70.3 million through Oct. 24, according to Rentrak.

Last year, three fall films had crossed the $70 million mark by the end of October: Warner Bros.’ “The Departed” ($77 million), Paramount’s “Jackass Number Two” ($71.2 million) and Sony’s toon “Open Season” ($70 million).

“The reason ‘Game Plan’ is doing so well is that it absolutely and positively had no competition,” one Mouse House exec concedes. “Nobody else has an upbeat feel-good movie.”

And while the low-budget comedy has bragging rights, those totals are a far cry from 2004, when DreamWorks’ toon “Shark Tale,” released on Oct. 1, racked up $139.4 million in its first four weeks of release.

In a rare case of eyeing one another’s release strategy, rival studios backed away from the Oct. 5 opening of DreamWorks-Paramount’s “The Heartbreak Kid.” It was unnecessary caution, since the film opened to only $14 million. (The comedy had grossed $32 million through Oct. 22.)

Many predict the box office will come back to life with the Oct. 26 release of “Saw IV,” and even moreso with the Nov. 2 bows of Ridley Scott’s Denzel Washington-Russell Crowe starrer “American Gangster” and DreamWorks Animation’s “Bee Movie.”

But, in hindsight, should some of these titles have opened earlier?

While no one is panicking, Hollywood is determined that next year it won’t repeat the September-October errors of this year. Next fall is already shaping up to have more studio comedies, family titles and even action.

In 2008, DreamWorks-Paramount is skedded to release the Eddie Murphy laffer “Nowhereland” on Sept. 26, while U has chosen the same date to unspool actioner “Death Race.” On Oct. 3, Warners will unspool the live-action fantasy “Where the Wild Things Are,” based on the beloved children’s book.

“I think the marketplace can always use family and action,” says MGM distribution topper Clark Woods, whose studio has just dated Jennifer Aniston-Steve Zahn laffer “Management” to bow on Sept. 19, 2008.

As for this fall, one studio exec says, “October has become the Bermuda triangle for adult dramas.”

The surprise success of Julie Taymor’s whimsical “Across the Universe” underscores that auds are hungry, even starving, for feel-good pics. “Universe,” a hit among girls, has grossed $16.7 million to date in its limited run.

From the first weekend after Labor Day through Oct. 22, total box office receipts were $785.7 million. It’s the first time the fall box office hasn’t crossed the $800 million mark by this point since 2001.

Fall hasn’t been an out-and-out disaster, but no one likes the fact that business has headed south, even if the domestic box office remains up 6% year-to-year, helped by the record-breaking summer, which was up a whopping 11%. Some studio execs wonder if people burned themselves out on going to the movies this summer. Another theory: Auds are distracted by fall television.

Sony is No. 1 in fall market share, thanks to “Resident Evil: Extinction” (a $23.7 million bow on Sept. 21, and a cume of $50 million through Oct. 22). Other Sony performers include horror title “30 Days of Night,” which won the Oct. 19-21 frame on its $16 million bow, and “We Own the Night,” which has fallen short of “Departed” numbers, but grossed $19.7 million through Oct. 22.

“30 Days” and “Resident,” the third highest-grossing film of the fall so far, continue a Sony tradition of taking top share due to seasonal horror titles.

Lionsgate moved into the No. 2 slot for market share, thanks to “3:10 to Yuma” (at $53 million, the second highest grosser of the period), “Good Luck Chuck” ($34 million through Oct. 22) and “Tyler Perry’s Why Did I Get Married?” (a $21.4 million debut on the weekend of Oct. 12, and a cume of $39 million through Oct. 22).

After Sony and Lionsgate, market-share ranking goes in this order for the majors: Universal, Disney, New Line, Paramount, Warners and Fox.

Outside of genre films like “Yuma” or horror titles, this fall has seen a glut of R-rated adult dramas vying for pretty much the same aud.

To date, 13 of the top 20 grossing fall films are rated R. Last year, only seven of the top 20 films that were released during the same time period were R-rated. In fact, this is the first year PG-13 titles haven’t dominated.

All told, 39 of the pictures released between Sept. 7 and Oct. 22 were rated R, while 18 were rated PG-13 and 11 PG. Last year, 31 released during the same frame were R, 20 were PG-13, while 10 were PG.

Like the majors’ wide releases, the playing field has been crowded on the specialty side. Each weekend brings a wave of new competing releases. There’s less room for specialty films to grow and platform. Some fall specialty films are doing well, but even those are having trouble keeping screens.

Grosses that normally would be just fine aren’t cutting the mustard this year. Last year, “The Queen” made only $4 million between its Sept. 30 release and Oct. 22, but it was considered a strong launch.

Paramount Vantage’s “Into the Wild” expanded from 153 theaters to 658 over the Oct. 19 weekend. The pic grossed $2.1 million for a per-screen average of $3,250 and has a cume of $6.5 million through Oct. 22.

“We’re really confident that our film has legs, but it is survival of the fittest out there,” Vantage prexy John Lesher says.

Warner’s “Michael Clayton,” starring George Clooney, opened wide rather than platforming. “Clayton” is showing signs of box office strength among adult-skewing dramas vying for awards attention, coming in No. 4 over the weekend of Oct. 19.

Ang Lee’s erotic thriller “Lust, Caution,” from Focus, is hanging in there, as are Fox Searchlight’s “The Darjeeling Limited” and MGM-Sidney Kimmel Entertainment’s dramedy “Lars and the Real Girl,” starring Ryan Gosling.

“We are all stretched too thin,” says one marketing exec. “It’s like a terrible self-fulfilling prophecy. Adult movies need word of mouth and time to build. This year, you don’t have that time. Also, in the little free time I have, why would I want to go to a theater and feel bad?”