In 1992 Hans Kloosterman managed to prove that 42 moves was the maximum required, while in April 2006 Silviu Radu had improves this to 27 moves. Since the very earliest days of the Rubik’s Cube scientists have been trying to work out the maximum number of moves needed to complete it. The magic figure of 20 is known as ‘God’s Number’ because it refers to the most efficient algorithm for solving a puzzle that always uses the shortest sequence of moves.
To solve the maximum moves needed would have taken a standard desktop PC around 35 years to solve but it took the team only a few weeks using Google’s supercomputers. The majority of configurations need only 18 moves to completeĮach of these individual problems were small enough to fit into the memory of a standard PC and the way the algorithms broke the sets down meant each could be solved in less than 20 seconds. ‘Instead of solving both of these positions, you can simply solve one, and then turn the solution upside down for the other.’Ī table which shows the number of different Rubik's Cube configurations and how many moves are needed to solve them. The researchers explained on their website: ‘If you take a scrambled Cube and turn it upside down, you have not made it any more difficult it will still take the same number of moves to solve. The team then used symmetry to reduce the number of problems down still further. He said that it would have been ‘completely hopeless’ to try and test every configuration individually so instead the team split the combinations into 2.21 billion groups of 20 billion positions. Professor Morley Davidson, a mathematician from Ohio’s Kent State University, worked alongside an engineer at Google and colleagues from Germany and California. The majority needed only between 15 and 19 moves. Only 300 million configurations, a tiny fraction of the total, require 20 moves. Scientists have long believed that 20 was the so-called ‘God number’ in theory but it has been impossible until now to find the processing power to prove it definitively. Using Google’s supercomputers, a team of researchers have processed every one of the Rubik’s Cube’s 43,252,003,274,489,856,000 different configurations to work what is the maximum number of moves needed to complete it. It is a figure that will leave veteran Rubik’s Cube addicts shaking their heads in disbelief.īut scientists have worked out that the famous puzzle can always be completed in 20 moves or less. If you are new to competing, you may want to look at CubingUSA's Competitor Tutorial.Scientists have proved that you only need 20 moves to solve the Rubik's Cube Therefore, all competitors should be familiar with the WCA regulations. This competition is recognized as an official World Cube Association competition.
If you do not attend, your registration fee will be donated to the Joyful Heart Foundation. Please note that your payment is considered to be a commitment to attend the competition and will not be refunded in the event that you cannot attend the competition. In addition, there will be a donation jar if visitors or competitors would like to further support the foundation. Information about the cause will be available at the competition. With the exception of overhead fees and $1 per competitor going to the WCA fee, the profits will be donated to the Joyful Heart Foundation. $10 for the first event, $5 per additional event if paying day of competition.