When the audience pulls out the card to see the idea, the performer divides the lower part of the card into sectors and prepares to insert it back. At the moment of inserting the card, use the middle finger of the right hand to quickly lean against the edge of the card, and the hands will be completely closed immediately. At this point, there is a gap between the inserted card and the next adjacent card. Because the middle finger of the right hand is stuck, the left hand holds the card and the right hand pulls it several times, and the card is pulled to the top. After shuffling, I still stay on it. When you turn to get the thumbtack, quickly take out a thumbtack that was put in the seam of your skirt in advance and put a playing card on it from front to back. Because the tail of the thumbtack is small and covered by the palm of the left hand, it is difficult for the audience to see the flaw. When throwing a card at the chessboard, the back of the card faces the chessboard.