Just thought of another one.... TJW 90, but in their case, it improved the show... somewhat.
The first TJW 90 format had paltry dollar figures between 5-50 spinning on the wheels, and that determined the value of each question. On the third wheel was a joker, which tripled the value of the spin. It also gave that spinner a chance to answer a series of definitions in 30 seconds (I think) unopposed. Instead of questions, TJW 90 was a "game of definitions". Basically, the game played out like the "fast forward" format, with no money lost on an incorrect answer.
Unfortunately, this format proved to be alienating for fans of the original TJW. There were 3 players instead of 2. The excitement of getting 3 jokers was gone, and what's so exciting about watching small amounts of money being spun on the wheels? Also pointless was the "opponent's choice" category where the opponent chose the category for the player, and spinning it also meant less money per question.
A little too late, they made some changes. Now, there were categories on the wheels, and 3 jokers. Unfortunately, they kept the definitions. However, they made the 3 player round last until someone scored 1000 instead of 500.
The Dating Game 97 underwent similar "going back to what worked and keeping some new elements" as well.
The first Dating Game format allowed the bachelor to actually SEE the three bachelorettes, but their identity was still kept secret. Instead of asking questions, the bachelor was shown up to 9 different statements, and the bachelor picked the statement he wanted to hear more about (For example "I like to party at Chuck E Cheeses")
Later in the run, they decided to have an entire week where they reverted back to the old Dating Game, not allowing the bachelor to see any of the bachelorettes, and decorating the set with daisies, but keeping the 9 statement format. They later made this change permanent.
To my knowledge, they never did this on Newlywed Game 97, which had 3 couples and 3 entirely different rounds, only one which resembled the old Newlywed Game.
