Theatrical windows for the biggest grossing pics continue to close.

Daily Variety analysis of theatrical windows — the period between a pic’s theatrical debut and its release on DVD — for films grossing more than $50 million at the domestic B.O. showed an 11% drop to 136 days (about 4½ months) in 2005, including all but one $50 million-plus film, “Syriana,” whose DVD date has not been announced.

That drop outpaces the 4% domestic B.O. decline (or perhaps goes hand in hand with it) and comes after windows for similar movies held steady in 2004.

At the same time, most movies continued to lose their legs at the B.O.

Of course, bombs that studios rush to homevideo and pics held back due to holiday themes or seasonal elements have always been part of the windows equation.

For example, Sony and Warner Bros. decided to delay releasing their seasonal pics “Christmas With the Kranks” and “The Polar Express,” respectively, on disc for a year after their November 2004 theatrical debuts. And New Line did the same with “Elf” the prior year, eventually releasing it on disc November 2004. (In 2005, there were no similar holiday examples.)

The overall figures come as NATO topper John Fithian gloated at last week’s ShoWest confab over “misguided experiments” in simultaneous theatrical and homevid release, while exulting in a “relatively stable” theatrical window after 2004’s four-day drop.

A recent report by Kagan Research estimated last year’s average window for all theatricals dipped to 129 days, a 15-day decline repping a 10.4% drop from 2004’s average. That follows a more modest 2.7% overall decline between 2003 and 2004, when the window shrank four days, Kagan reported in its Motion Picture Investor newsletter late last year.

Meanwhile, even as they reassure Fithian about the need to preserve a theatrical window, studios continue to experiment with ways to shorten it and maximize coin in both realms. At the Bears Stearns investor conference late last month, News Corp. prexy-chief operating officer Peter Chernin cited Fox’s aggressive theatrical window for “Walk the Line” as a way, along with high-def video-on-demand, to monetize content “in ways we never thought of” (Daily Variety, March 1).

Among $50 million-plus movies last year, “Walk the Line” had the third lowest window at 102 days, just under “Be Cool” at 93 and “Yours, Mine and Ours” at 97.

Disney topper Bob Iger, who kicked off a firestorm last year with talk of collapsing windows, hasn’t backed off but he has softened his stance a bit. In his keynote address Monday at the TelecomNext trade show in Vegas, Iger did not address windows directly but stressed that the studio must continue to evaluate business models or risk losing opportunities.

He was even more pointed in a Dec. 5 interview with the Wall Street Journal, predicting a lot of trial and error as studios test the marketplace to see what it will tolerate.

Eager to avoid diminishing the theatrical take — or further angering exhibs — studios have become more tightlipped about their DVD release plans. Universal refused to confirm “King Kong’s” March 28 bow for weeks, even as rival studios touted tie-ins, and only went official with its April 4 release of “Brokeback Mountain” two weeks ahead of its disc debut. Fox homevid cut it similarly close with “Walk the Line,” a pic that was playing well at theaters.

For all the attention generated by “Bubble’s” simultaneous bow in theaters and homevid late in January, that release was never considered a true test of the tiered distribution system because Steven Soderbergh’s movie is experimental and stars non-pros. Distrib Magnolia Pictures contends “Bubble” has been a success on homevid but has been vague on supporting figures.

The movie’s lackluster B.O. — it generated about $145,000 at theaters — did calm the waters with exhibs, however. In his ShoWest address, Fithian even went so far as to thank Mark Cuban and Soderbergh for teeing up the debate about simultaneous windows.

Meanwhile, windows continue to shrink as pics’ theatrical legs grow shorter. According to Kagan, the average theatrical window was 180 days, or about six months, in 1996 and was hovering in the mid-160s as of 2002 before taking a sharp turn lower.

According to Kagan, the window grew shorter as the B.O. went lower last year. Research org estimated that films with $10 million-$29 million in domestic B.O. averaged 115 days to hit homevid, while those grossing more than $30 million took an average of 132 days. Org found that windows for pics in the $100 million-plus range dropped most, by 30 days to 132 in 2005, while those in the $10 million-$29 million range dipped 20 days to 135.