Speedcubing (also known as speedsolving) is the activity of solving a Rubik's Cube or related puzzle as quickly as possible. Here, solving is defined as performing a series of moves that transforms a scrambled puzzle into a state where each of the puzzle's six faces is one single, solid color.
Most cubes are sold commercially in variations of 2×2×2, 3×3×3, 4×4×4, 5×5×5, 6×6×6, and 7×7×7, although variations of the puzzle have been designed with as many as 17 layers. The current world record for a single solve of the 3×3×3 in competition is 5.55 seconds set by Mats Valk during the Zonhoven Open 2013.
Speedcubing is a popular activity among the international Rubik's Cube community. Members come together to hold competitions, work to develop new solving methods, and seek to perfect their technique. As a part of the community, puzzle builders try to invent new forms of combination puzzles.
The Rubik's Cube was invented in 1974 by Hungarian professor of architecture Ernő Rubik. A widespread international interest in the cube began in 1980, which soon developed into a global craze. On June 5, 1982, the first world championship was held in Budapest, Hungary. The height of the craze began to fade away after 1983, but with the advent of the Internet, sites relating to speedcubing began to surface. Simultaneously spreading effective speedsolving methods and teaching people new to the cube to solve it for the first time, these sites brought in a new generation of cubers, created a growing international online community, and raised the profile of the art. Twenty years after the first World Championship, the 2002 Dutch Open competition was the first in a new wave of organized speedcubing events, which include regular national and international competitions. There have been five more World Championships since Budapest's 1982 competition, which are traditionally held every other year, the first held in Toronto, Ontario, in 2003. This new wave of speedcubing competitions have been organised by the World Cube Association founded by Ron van Bruchem.
The standard Rubik's Cube can be solved using a number of methods, not all of which are intended for speedcubing. Although some methods employ a layer-by-layer system and algorithms, other significant (though less widely used) methods include corners-first methods, and the Roux method.
The CFOP (Cross - F2L - OLL - PLL) method, also known as the Fridrich Method, was named after one of its inventors, Jessica Fridrich, who finished 2nd in the 2003 Rubik's Cube World Championships. The first step of the method is to solve a cross-shaped arrangement of pieces on the first layer. The remainder of the first layer and all of the second layer are then solved together in what are referred to as "corner-edge pairs" or slots. Finally, the last layer is solved in two steps — first, all of the pieces in the layer are oriented to form a solid color (but without the individual pieces always being in their correct places on the cube). This step is referred to as orientation and is usually performed with a single set of algorithms known as OLL (Orientation of Last Layer). Then, all of those pieces are permuted to their correct spots. This is also usually performed as a single set of algorithms known as PLL (Permutation of Last Layer).
The CFOP method is a widely used speedcubing method. Its popularity stems from the speed at which it can be easily performed. Besides the first step, which can be planned during the customary 15-second inspection time, the entire solve of the cube consists of executing predefined algorithms based on the state of the cube. However, intuition can still be brought into play to decrease the total number of moves required to complete the solve, either by attempting to force the next step to be an easier case while completing the current step, or sometimes even solving more than one corner-edge pair simultaneously.
The Roux method was invented by French speedcuber Gilles Roux. The first step of the Roux method is to form a 3×2×1 block placed in the lower portion of the left layer. The second step is to create another 3×2×1 on the opposite side. The remaining four corners are then solved using a set of algorithms known as CMLL (Corners of the Last Layer, without regard to the M-slice), which leaves six edges and four centers that are solved in the last step.
This method is not as dependent on algorithm memorization as the CFOP method, since all but the third step is done with intuition as opposed to predefined sets of algorithms. The Roux method can more easily be performed without rotations (unlike the CFOP method) which means it is easier to look ahead (solving a collection of pieces while at the same time looking for the solution to the next step) while solving.
The ZZ method is a modern speedcubing method originally proposed by Zbigniew Zborowski in 2006. The method was designed specifically to achieve high turning speed by focusing on move ergonomics. The initial pre-planned step is called EOLine, and is the most distinctive hallmark of the ZZ method. It involves orienting all edges while placing two opposite down-face edges. The next step solves the remaining first two layers using only left, right and top face turns. On completion of the first two layers, the last layer's edges are all correctly oriented because of edge pre-orientation during EOLine. The last layer may be completed using a number of techniques including those used in the CFOP method. An expert variant of this method (ZZ-a) allows the last layer to be completed in a single step with an average of just over 12 moves and knowledge of 177 algorithms.
The Petrus method, named after its inventor Lars Petrus, is considered to be more intuitive than the structured CFOP method. The first step of the Petrus method is to solve a 2×2×2 block of the cube. This block is then extended to a solved 2×2×3 block. All edges are then oriented and the first and second layers are completed. Next, the top corners are put in the right place and the layer is oriented correctly (all stickers facing up) and finally the last edges are permuted (moved around). Lars Petrus developed this method to address what he felt were inherent inefficiencies in layer-by-layer approaches. This method is often used as the basis for fewest moves competition .
Corners-first methods involve solving the corners then finishing the edges with slice turns. Corners-first solutions were common in the 1980s, with one of the most popular methods that of 1982 world champion Minh Thai. Currently corners-first solutions are less common among speedsolvers. Dutch cuber Marc Waterman created a corners-first method in the cube craze, and averaged 16 seconds in the mid-late 1980s.
According to the World Cube Association (WCA), competitors (in the same round) must solve cubes that are scrambled using a consistent set of moves (every competitor solves the same scramble). Currently, the official timer used in competitions is the StackMat timer. This device has touch-sensitive pads that are triggered by the speedcuber lifting their hands to start the time and placing their hands back on the pads after releasing the puzzle to stop the timer. In addition to the electronic timer, there are human judges with stopwatches who time the 15-second inspection period before each solve, as well as solves which may take longer than 10 minutes. These judges also ensure that the competitors are following competition regulations.
Official competitions are currently being held in several categories.
|speedsolving||2×2×2, 3×3×3, 4×4×4, 5×5×5, 6×6×6, 7×7×7|
|blindfolded solving||3×3×3, 4×4×4, 5×5×5|
|solving with feet||3×3×3|
|solving in fewest moves||3×3×3|
Competitions will often include events for speedsolving these other puzzles, as well:
World Rubik's Cube Championships
The WCA organizes the World Rubik's Cube Championship as the main international competition once every two years. The latest championship was held in Las Vegas, Nevada, from July 26-28, 2013.
|I||1982||Budapest||June 5||19||1||1||Minh Thai||22.95|||
|II||2003||Toronto||August 23–24||15||9||13||Dan Knights||20.00|||
|III||2005||Lake Buena Vista||November 5–6||16||9||15||Jean Pons||15.10|||
|IV||2007||Budapest||October 5–7||28||10||17||Yu Nakajima||12.46|||
|V||2009||Düsseldorf||October 9–11||32||12||19||Breandan Vallance||10.74|||
|VI||2011||Bangkok||October 14–16||35||12||19||Michał Pleskowicz||8.65|||
|VII||2013||Las Vegas||July 26-28||35||10||17||Feliks Zemdegs||8.18|||
Note: For averages of 5 solves, the best time and the worst time are dropped, and the mean of the remaining 3 solves is taken. When only 3 solves are done, the mean of all 3 is taken as normal.
|Event||Type||Result (Min:Sec)||Person||Competition||Result Details (Min:Sec)|
|2×2×2||Single||00:00.69||Christian Kaserer||Trentin Open 2011|
|Average||00:01.69||Rami Sbahi||Holy Toledo Winter 2014||00:01.58 / 00:01.82 / 00:01.91 / 00:01.50 / 00:01.66|
|3×3×3||Single||00:05.55||Mats Valk||Zonhoven Open 2013|
|Average||00:06.54||Feliks Zemdegs||Melbourne Cube Day 2013||00:06.91 / 00:06.41 / 00:06.25 / 00:07.30 / 00:06.31|
|4×4×4||Single||00:24.66||Feliks Zemdegs||Lifestyle Seasons Summer 2014|
|Average||00:28.15||Sebastian Weyer||Frankfurt Cube Days 2014||00:27.90 / 00:27.13 / 00:29.63 / 00:26.46 / 00:29.41|
|5×5×5||Single||00:50.50||Feliks Zemdegs||Australian Nationals 2013|
|Average||00:55.33||Feliks Zemdegs||Melbourne Cube Day 2013||00:55.63 / 00:53.55 / 01:09.15 / 00:51.69 / 00:56.80|
|6×6×6||Single||01:40.86||Kevin Hays||Vancouver Summer 2013|
|Average||01:51.30||Kevin Hays||Vancouver Summer 2013||01:40.86 / 02:01.94 / 01:51.11|
|7×7×7||Single||02:39.41||Lin Chen||Shanghai Spring 2014|
|Average||02:52.09||Feliks Zemdegs||Australian Nationals 2013||02:54.27 / 02:42.44 / 02:59.55|
|Megaminx||Single||00:42.28||Simon Westlund||Danish Open 2011|
|Average||00:47.82||Bálint Bodor||Hungarian Open 2012||00:51.90 / 00:49.55 / 00:47.50 / 00:45.88 / 00:46.40|
|Pyraminx||Single||00:01.36||Oscar Roth Andersen||Danish Special 2013|
|Average||00:02.96||Oscar Roth Andersen||Danish Special 2013||00:03.38 / 00:01.36 / 00:03.00 / 00:02.86 / 00:03.02|
|Square-1||Single||00:07.41||Andrea Santambrogio||Legnano Open 2013|
|Average||00:11.31||Bingliang Li||Guiyang Open 2012||00:11.24 / 00:10.43 / 00:10.87 / 00:11.82 / 00:13.62|
|Rubik's Clock||Single||00:05.27||Sam Zhixiao Wang||Shanghai Winter 2011|
|Average||00:06.68||Evan Liu||Nottingham Open 2014||00:07.11 / 00:05.78 / 00:06.73 / DNF / 00:06.20|
|Skewb||Single||00:02.19||Brandon Harnish||Bay Area 2 2014|
|Average||00:04.58||Jonatan Kłosko||SLS Tarnowskie Gory 2014||00:04.55 / 00:04.38 / 00:03.81 / 00:04.81 / 00:05.68|
|3×3×3: Blindfolded||Single||00:23.80||Marcin Zalewski||Polish Nationals 2013|
|Average||00:28.87||Marcin Kowalczyk||GLS Autumn Reda 2013||00:32.22 / 00:24.71 / 00:29.69|
|4×4×4: Blindfolded||Single||02:30.62||Marcell Endrey||Slovenian Open 2013|
|5×5×5: Blindfolded||Single||06:06.41||Marcell Endrey||World Championship 2013|
|3×3×3: Multiple Blindfolded||Single||41/41||Marcin Kowalczyk||SLS Swierklany 2013||54:14.00|
|3×3×3: One-handed||Single||00:09.03||Feliks Zemdegs||Lifestyle Seasons Summer 2014|
|Average||00:12.67||Michał Pleskowicz||Cubing Spring Grudziadz 2012||00:12.15 / 00:14.53 / 00:13.27 / 00:12.58 / 00:10.77|
|3×3×3: With feet||Single||00:27.17||Gabriel Pereira Campanha||Santo Amaro 2014|
|Average||00:30.57||Gabriel Pereira Campanha||Valeparaibano 2013||00:32.25 / 00:28.01 / 00:30.45|
|3×3×3: Fewest moves||Single||20||Tomoaki Okayama||Czech Open 2012|
|Average||25.69||Sébastien Auroux||Villa de Catral 2013||23 / 25 / 29|
Some speedcubers lubricate their cubes to prevent wrist and finger injury. Lubricating the cube also allows it to be manipulated more quickly than a non-lubricated cube. The WCA allows lubrication for official competitions.
Some of the popular lubricants among speedcubers are:
- Lubix Cube Lubricant
- CRC Heavy Duty Silicone Spray
- D-39 Silicone Spray
- Cyclo Silicone Spray
- Maru Lubricant
- Traxxas 50K Differential Oil
- Cubesmith Lubricant
Checking a lubricant's MSDS is often helpful in identifying cube-damaging ingredients.
Below are some definitions of words generally used by the speedcubing community. For a more complete list of speedcubing terminology, see the cubefreak.net glossary.
- A predefined sequence of moves used to effect a specific change on the cube. Often referred to as alg or (less commonly) an algo.
- Blindfolded solving, i.e. memorize, blindfold, then solve.
- Center piece
- One of the six centers of the faces of the cube. The centers never move relative to each other on an NxNxN cube, where N is odd. On NxNxN cubes with N>3, every piece with only one sticker is referred to as a 'center piece', including those pieces that can move relative to each other.
- Corners of the Last Layer. This is the first of two steps of one of the methods of solving the last layer of the cube. In the process, edges may be unoriented. This is used in Corners First methods for the last layer, in which the first all corners are solved, followed by the edges (see ELL). CLL is also commonly used to solve the last layer of a 2x2x2 cube in one step.
- Corner piece
- One of the 8 pieces with exactly three stickers, called a "corner" piece because a corner is exposed.
- One of the mechanically independent pieces that make up a puzzle. The cubies do not include fixed center pieces, nor the central axis to which they are attached.
- To rotate pieces' positions on the cube. e.g. a 3-cycle would make cubie set A-B-C become C-A-B.
- Did Not Finish, used in competition. e.g. when a piece pop occurs and the competitor decides not to continue the solving of the puzzle, or when a blindfolded solver stops the timer with the cube still unsolved.
- Did Not Start, used in competition when the competitor does not begin a solve, either by opting to skip it (common in Blindfold Cubing) or by not showing up when he or she is called, or not qualifying for the remaining (usually 3) solves of a certain round.
- Edge piece
- One of the 12 pieces with exactly two stickers, called an "edge" piece because only one edge is exposed.
- Edges of the Last Layer. The second of two steps of one of the methods of solving the last layer of the cube, solving the edge pieces without disturbing the corner pieces (see CLL).
- First two blocks. This is used in the Roux method.
- First two layers. This is used in the CFOP (Fridrich), Petrus, and ZZ methods.
- One section of a cube consisting of a number of cubies that turn as a unit. (e.g. a standard Rubik's Cube has 3 layers)
- Last Layer. Usually refers to the top layer of the cube, but for the Roux method can refer to the middle layer between the left and right faces.
- A combination of steps that can be used to solve a cube.
- A turn of one of the six faces or three slices of the cube.
- N-look, also known as X-Look
- Refers to the number of algorithms needed to complete a step in a particular solving method, often the last layer, e.g. '4-look LL'.
- Orientation of the Last Layer, usually used in reference to the respective step of the CFOP method.
- To change the orientation of a piece.
- Personal Best - personal record time to solve a puzzle. This can either be a single attempt or a trimmed average, depending on context.
- To relocate certain pieces in a way to achieve a desired result.
- Permutation of the Last Layer. Usually used in reference to the respective step of the CFOP method, in which case it would follow the OLL step.
- When, during a speedsolve, one or more cubies come out of the puzzle.
- A counter-clockwise move popularly denoted with a ', e.g. 'R Prime', denoted as R', R-, , or Ri. Also (less commonly) known as "inverse" or "inverted".
- The four center pieces and four edge pieces between two opposite layers of the cube.
- Two-Second Penalty, also known as +2
- A penalty of 2 seconds which is added to a solving time in official competitions when the cube is placed back on the timing pad with one or more faces misaligned 45 degrees or more. It can also be given in other cases, such as when the competitor starts the timer too slow or does not correctly stop the timer after finishing the solve.
- Unofficial World Record.
- World Cube Association, the international governing body for official cube competitions.
- World Record. Can also be "World Rank" when referring to the rank of a person's record in a database.
- Rubik's Cube
- World Cube Association
- Feliks Zemdegs
- Mats Valk
- Eric Limeback - Current 24 hour world record holder
- "Over The Top - 17x17x17".
- "Records". Retrieved 2013-04-02.
- "Kopie van Mats Valk official Rubik`s cube single WR: 5.55".
- "Competitions". Retrieved 2007-11-27.
- "Rubik's Cube: Algorithms for the last layer". Retrieved 2009-06-02.
- "World Rubik's Cube Championship 1982". World Cube Association. Retrieved 2010-12-27.
- "World Rubik's Games Championship 2003". World Cube Association. Retrieved 2010-12-27.
- "World Rubik's Cube Championship 2007". World Cube Association. Retrieved 2010-12-27.
- "World Rubik's Cube Championship 2009". World Cube Association. Retrieved 2010-12-27.
- "World Rubik's Cube Championship 2011". World Cube Association. Retrieved 2011-01-24.
- "World Rubik's Cube Championship 2013". World Cube Association. Retrieved 2013-07-29.