Or 1950: when What's My Line basically invented the panel show
“Information, Please” ran on NBC Blue, NBC Red, CBS and Mutual from May 1938 to June 1948. Later shows were repeats. (Source:
On the Air: The Encyclopedia of Old Time Radio by John Dunning, page 341)
I would vote for 1965 as a year of several notable changes, some of them structural that would reverberate for a number of years:
*Bob Stewart and Chuck Barris made their first sales as independent producers (“Eye Guess”, “The Dating Game”).
*The debuts of “Supermarket Sweep” and “The Dating Game” in December 1965 marked a change in tone from ABC’s previous daytime games. Most of the ones they aired from 1957-65 were relatively conventional, and several were picked up from the other networks. The two new programs seemed more youth-oriented, and the sight of contestants running through a supermarket was certainly a change of pace.
*”PDQ”, which started this year, was the first Heatter-Quigley game to last more than two years, and the first syndicated game to last more than a few months.
*”The Price is Right” was among the last (if not the last?) daytime games to air live most days of the week. Bill Cullen’s next project, “Eye Guess”, seems to have been entirely pre-recorded.
The only B&W game to transition to color was “The Match Game” in April, but the I think the balance in favor of color game shows tipped during 1963 or 1964. (It helped, of course, that NBC tended to air more games than CBS or ABC.)