First International RoShamBo Programming Competition in 1999, uses a heuristically designed compilation of strategies. For each strategy it employs, it also has six metastrategies which defeat second-guessing, triple-guessing, as well as second-guessing the opponent, and so on. The optimal strategy or metastrategy is chosen based on past performance. The main strategies it employs are history matching, frequency analysis, and random guessing. Its strongest strategy, history matching, searches for a sequence in the past that matches the last few moves in order to predict the next move of the algorithm. In frequency analysis, the program simply identifies the most frequently played move. The random guess is a fallback method that is used to prevent a devastating loss in the event that the other strategies fail. There have since been some innovations, such as using multiple history-matching schemes that each match a different aspect of the history – for example, the opponent's moves, the program's own moves, or a combination of both. There have also been other algorithms based on Markov chains. In 2012, researchers from the Ishikawa Watanabe Laboratory at the University of Tokyo created a robot hand that can play rock paper scissors with a 100% win rate against a human opponent. Using a high-speed camera the robot recognizes within one millisecond which shape the human hand is making, then produces the corresponding winning shape. Variations Players have developed numerous cultural and personal variations on the game, from simply playing the same game with different objects, to expanding into more weapons and rules, to giving their own name to the game in their national language. Adapted rules In Korea, where the standard version of the game is called gawi-bawi-bo, a two-player upgraded version exists by the name muk-jji-ppa. After showing their hands, the player with the winning throw shouts "muk-jji-ppa!" upon which both players throw again. If they throw differently (for example, rock and paper, or paper and scissors), whoever wins this second round shouts "muk-jji-ppa!" and thus the play continues until both players throw the same item (for example, rock and rock), at which point whoever was the last winner becomes the actual winner. In another popular two-handed variant, one player will shout "minus one" after the initial play. Each player removes one hand, and the winner is decided by the remaining hands in play. In Japan, a strip game variant of rock paper scissors is known as 野球拳