I remember seeing former Miss America/former CBS TV personality Phyllis George make her debut on "The $10,000 Pyramid," and she was HORRIBLE.
I was amazed that they would ever ask her back, but they did - and she had improved considerably; still not a great player, but a competent one. Obviously, she'd practiced.
Side note: I recall Pittsburgh Steeler Lynn Swann on Pyramid. It was his first time out, but he proclaimed himself a fan of the show, and demonstrated it by doing a fine job.