Editing Rock paper scissors (section)

=== Algorithms ===
As a consequence of rock paper scissors programming contests, many strong algorithms have emerged.<ref name="rpscontest"/><ref name="roshambo1"/><ref name="roshambo2"/> For example, Iocaine Powder, which won the First International RoShamBo Programming Competition in 1999,<ref name="roshambo1"/> uses a heuristically designed compilation of strategies.<ref>{{cite web|title=Iocaine Powder Explained|url=http://www.ofb.net/~egnor/iocaine.html|author=Egnor, Dan|access-date=2011-06-15|date=1999-10-01|url-status=dead|archive-url=https://web.archive.org/web/20110723203327/http://www.ofb.net/~egnor/iocaine.html|archive-date=2011-07-23}}</ref> 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&nbsp;– for example, the opponent's moves, the program's own moves, or a combination of both.<ref name="werfer">{{cite web|title=Rock Paper Scissors Programming Competition entry: DNA werfer 5 L500|url=http://www.rpscontest.com/entry/109010|author=dllu|access-date=2011-06-15|date=2011-06-14|archive-date=2012-03-25|archive-url=https://web.archive.org/web/20120325184613/http://www.rpscontest.com/entry/109010|url-status=live}}</ref> There have also been other algorithms based on [[Markov chain]]s.<ref>{{cite web|title=Rock Paper Scissors Programming Competition entry: sixth-order markov chain|url=http://www.rpscontest.com/entry/34014|author=rfw|access-date=2011-06-15|date=2011-05-22|archive-date=2012-03-25|archive-url=https://web.archive.org/web/20120325184648/http://www.rpscontest.com/entry/34014|url-status=live}}</ref>

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.<ref>{{cite news| url=https://www.theguardian.com/technology/video/2012/jun/27/rock-paper-scissors-robot-video | location=London | work=The Guardian | title=Rock-paper-scissors robot wins every time – video | date=2012-06-27}}</ref><ref>{{cite web | url = http://www.k2.t.u-tokyo.ac.jp/fusion/Janken/index-e.html | title = Janken (rock-paper-scissors) robot with 100% winning rate (human-machine cooperation system) | website = The University of Tokyo | access-date = 12 January 2018 | archive-date = 12 January 2018 | archive-url = https://web.archive.org/web/20180112100934/http://www.k2.t.u-tokyo.ac.jp/fusion/Janken/index-e.html | url-status = dead }}</ref>