When the show expanded to one hour in 1975, was there a reason they waited two months into season 4 to make the change? The first permanent one hour show aired November 3, 1975. It seems like they would have wanted to have the first one hour show to kick off the season 4 premiere in early September 1975.
I believe the week of hour long shows in Sept was a test to see if an hour long game show could work. Assuming the ratings were decent and they got the green light from CBS, they probably starting taping the regular hour long shows late Sept to debut Nov 75.
Actually, the first permanent hour show didn't tape until October 20, 1975. And as far as I'm aware, October 12 was the day the last four half-hour shows were taped, so the decision to expand full time may not have been made until mid-October..