Found something interesting in the 10-16-1978 issue of
Broadcasting: ratings and rankings for daytime series covering January-August 1978 (the list doesn't include already-canceled series like Tattletales, Pass the Buck, et al.). Full details can be seen at the link below; here are the game shows:
https://www.americanradiohistory.com/hd2/IDX-Business/Magazines/Archive-BC-IDX/78-OCR/1978-10-16-BC-OCR-Page-0038.pdf01. Family Feud (9.1 rating, 38 share)
15. The Price is Right, second half (6.1, 28)
15. Wheel of Fortune (6.1, 27)
17. Match Game (5.8, 19)
19. The Price is Right, first half (5.7, 28)
20. The $20,000 Pyramid (5.6, 22)
22. The Hollywood Squares (5.4, 27)
23. High Rollers (5.1, 24)
24. Card Sharks (4.3, 24)
25. Tic Tac Dough (3.9, 21)
Observations:
--Probably stemming from its time changes, Match Game has fallen a ways from its 1975 ratings (mentioned in the 8-11-1975 issue of
Broadcasting as 11.3 with a 35 share).
--In its first months, Card Sharks did only somewhat better than Tic Tac Dough, but CS managed to hang on for 3-1/2 years.
--The two shows that Card Sharks and High Rollers replaced on the NBC lineup were Knockout, which averaged 5.0/22, and To Say the Least, which averaged 3.9/16 (both numbers from the 4-3-1978 issue of
Broadcasting, page 52). Wheel of Fortune improved numbers in 11:30 slot when it moved there to replace Knockout, and probably would've done even better if it hadn't faced Family Feud.