Yips is the state where the user freezes up and simply cannot move. According to Volk, when a player keeps up a perfect appearance and shows no opening in their play, doubt creeps into the opponent and significantly affects the opponent's motivation and self-confidence, both dropping until the opponent is afflicted and plunged deep into the state of yips. Kintarou Tooyama describes his experience of yips as "...like your body no longer wants to cross the net or move at all." Yips can be induced into the opponent in either singles or doubles matches.