According to a recent posting on Usenet by California TV buff Jim Ellwanger, this is an off-the-air recording of WCBS-TV in New York from the last week of March 1973 — the very first week of “The $10,000 Pyramid”:

(Watch really, really quickly at the beginning for an station ID slide for WCBS-TV and the syndicated version of “What’s My Line?”)

Ellwanger notes that the master tape of this episode is lost; indeed, like most daily programs made before the late 1970s, videotapes of “Pyramid” and other games shows were routinely erased and reused.

At his game show website, TV historian Curt Alliaume notes that “Pyramid” debuted on CBS at 10:30 a.m. March 26, 1973, displacing “The Price is Right,” which moved to 3 p.m. weekdays. Dick Clark was selected to host; though the show was taped in New York, Clark was in Hollywood, and commuted back and forth by airplane.

The show was taped in CBS’ “Ed Sullivan Theater” at 1697 Broadway in New York, currently the permanent home of “The Late Show With David Letterman.”

“Pyramid” started out with strong ratings, Alliaume notes, though it was pre-empted frequently for coverage of the U.S. Senate’s hearings into the break-ins at Democratic Party headquarters by people connected with President Nixon’s re-election campaign.

But when NBC moved “Jeopardy!” with Art Fleming to 10:30 a.m., “Pyramid”‘s ratings began to slip, and CBS cancelled the show.

It moved to ABC in the afternoons, first at 4 p.m., and then 2 p.m. when “The Newlywed Game” was cancelled in December 1974. (That show returned in syndication in 1977, of course.)

From there, “The $10,000 Pyramid” became the Number 3-rated show on daytime TV — a position it held for three years. The top prize was doubled (and the show’s name changed to “The $20,000 Pyramid”) in 1976, but the program was cancelled in 1980.

After a brief syndicated run as “The $50,000 Pyramid,” it moved back to CBS as “The $25,000 Pyramid” and lasted until 1988. There have been periodic revivals on network TV and in syndication since then.

These days, though game shows remain strong on nighttime network lineups in the U.S., daytime network game shows are almost entirely gone.

About the last one left is “The Price is Right,” which seems to be thriving on CBS with its new host, Drew Carey.