Editing Checkers (section)

== Computer checkers ==
{{Further|English draughts#Computer players|International draughts#Computers}}

[[File:Christopher Strachey's Draughts Program.png|thumb|[[Christopher Strachey]]'s checkers (1952) the first video game]]

[[File:Lefty_the_Robot_-_First_Checker_Playing_Robot_1983.png|thumb|[[Scott M Savage]]'s checkers (1983) the first robot game]]

American checkers has been the arena for several notable advances in [[game artificial intelligence]]. In 1951 [[Christopher Strachey]] wrote the first video game program on checkers. The checkers program tried to run for the first time on 30 July 1951 at NPL, but was unsuccessful due to program errors. In the summer of 1952 he successfully ran the program on [[Ferranti Mark 1]] computer and played the first computer checkers and arguably the [[Early history of video games|first video game ever]] according to certain definitions.  In the 1950s, [[Arthur Samuel (computer scientist)|Arthur Samuel]] created one of the first board game-playing programs of any kind.  More recently, in 2007 scientists at the University of Alberta<ref>[http://www.cs.ualberta.ca/~chinook/ Chinook - World Man-Machine Checkers Champion] {{webarchive|url=https://web.archive.org/web/20030624192451/http://www.cs.ualberta.ca/~chinook/|date=24 June 2003}}</ref> developed their "[[Chinook (draughts player)|Chinook]]" program to the point where it is unbeatable. A [[Brute-force search|brute force]] approach that took hundreds of computers working nearly two decades was used to [[Solved game|solve]] the game,<ref>{{cite journal|last1=Schaeffer|first1=Jonathan|last2=Burch|first2=Neil|last3=Björnsson|first3=Yngvi|last4=Kishimoto|first4=Akihiro|last5=Müller|first5=Martin|last6=Lake|first6=Robert|last7=Lu|first7=Paul|last8=Sutphen|first8=Steve|date=14 September 2007|title=Checkers Is Solved|journal=Science|volume=317|issue=5844|pages=1518–1522|doi=10.1126/science.1144079|pmid=17641166|bibcode=2007Sci...317.1518S|s2cid=10274228|doi-access=free}}</ref> showing that a game of checkers will always end in a [[Draw (tie)|draw]] if neither player makes a mistake.<ref>Jonathan Schaeffer, Yngvi Bjornsson, Neil Burch, Akihiro Kishimoto, Martin Muller, Rob Lake, Paul Lu and Steve Sutphen. Solving Checkers, International Joint Conference on Artificial Intelligence (IJCAI), pp. 292–297, 2005. Distinguished Paper Prize</ref><ref>{{cite web|title=Chinook - Solving Checkers Publications|url=http://www.cs.ualberta.ca/~chinook/publications/solving_checkers.html|url-status=dead|archive-url=https://web.archive.org/web/20080416083152/http://www.cs.ualberta.ca/~chinook/publications/solving_checkers.html|archive-date=16 April 2008|access-date=22 December 2007|website=www.cs.ualberta.ca}}</ref> The solution is for the checkers variation called go-as-you-please (GAYP) checkers and not for the variation called three-move restriction checkers, however it is a legal three-move restriction game because only openings believed to lose are barred under the three-move restriction. As of December 2007, this makes American checkers the most complex game ever [[Solved game|solved]].

In November 1983, the Science Museum Oklahoma (then called the Omniplex) unveiled a new exhibit: Lefty the Checker Playing Robot. Programmed by Scott M Savage, Lefty used an Armdroid robotic arm by Colne Robotics and was powered by a [[6502 processor]] with a combination of Basic and Assembly code to interactively play a round of checkers with visitors to the museum. Originally, the program was deliberately simple so that the average museum visitor could potentially win, but over time was improved. The improvements however proved to be more frustrating for the visitors, so the original code was reimplemented.<ref>{{cite news |author=<!--not stated--> |title=But Can It Type |url=https://www.newspapers.com/image/454398470/ |work=The Daily Oklahoman |agency=The Daily Oklahoman |date=25 November 1983|page=51|access-date=26 March 2022}}</ref>