Wheel of Fortune (US game show)
At the beginning of the show, there is a Toss-Up puzzle.  During this puzzle, one letter at a time is shown on the board. Any contestant may ring in to solve the puzzle before the last letter is revealed. An wrong answer means that person can not play for the rest of that round. After the puzzle is solved, a second Toss-Up is used to determines who starts the next round of the game.