Grand Slam is an Americangame show based on the British series of the same name. Unlike the British series, which was played as a regular quiz show, the American version was conducted as a super tournament featuring contestants who had earlier appeared on other game shows.
The program features 16 of the biggest winners in United States game show history in a single-elimination style tournament. The contestants are seeded by the amount of money won on their original show(s). The sole winner takes home the $100,000 Grand Prize and a crystal trophy.
The contestants face off against each other in a rapid-fire style series of questions. There are four rounds of questioning: General Knowledge, Numbers and Logic, Words and Letters, and "Mixed" (questions from all of the previous categories). Exclusively for the final match, a fifth "Contemporary Knowledge" round was added as round #3, between "Numbers and Logic" and "Words and Letters". In each round, the players are given one minute on their clocks, and the first contestant (determined by coin toss for the first round; alternates for each subsequent round) is asked a question by the off-camera "Questioner", and his clock starts counting down. The timing mechanics are similar to that of a chess clock; if a contestant answers correctly, his clock stops, and his opponent's clock starts running. However, if the active contestant answers incorrectly or passes, their clock continues to run and another question is asked.
When one contestant's clock expires, the round ends and whatever time the other player had remaining is carried over. At the beginning of the final round, whatever carried-over time the players have is added to the one minute base time. Once a player's clock runs out, the other player is declared the winner and moves on to the next round of the tournament.
Each contestant is given three "switches" at the beginning of the game, and one more before the fourth round; a contestant can use one by saying "switch" during their turn. This stops their own clock and begins their opponent's turn with the current question. Switches can be used consecutively (by saying "switch back") to switch the question back and forth between contestants.
Ken Jennings—74-time Jeopardy! champion, winning $3.022 million. In his initial run as champion Jennings set a new all-time winnings record.
Kevin Olmstead—contestant on Jeopardy! and on Who Wants to Be a Millionaire?. Olmstead is the biggest winner on Who Wants to Be a Millionaire, taking home a jackpot of $2.18 million; this broke a record set by David Legler and stood until Jennings topped it.
Ed Toutant—winner of $1.86 million on Who Wants to Be a Millionaire? in 2001. At the time his win made him the second biggest winner after Kevin Olmstead.
John Carpenter—first contestant to win $1 million on the American version of Who Wants to Be a Millionaire? in 1999. Carpenter later won $250,000 during Millionaire's Tournament of Champions. Carpenter was the first contestant to win $1 million in a single appearance on a game show.
Rahim Oberholtzer—won $1.12 million on Twenty One in 2000. At the time of his win, Oberholtzer was the first contestant to win over $1 million on a game show.
Nancy Christy—first female winner of $1 million on Who Wants to Be a Millionaire?, accomplishing this feat in 2003.
Ogi Ogas—won $500,000 on Who Wants to Be a Millionaire? in 2006.