Speedcubing (also known as speedsolving) is the activity of solving a Rubik's Cube or related puzzle as quickly as possible. For most puzzles, solving entails performing a series of moves that alters a scrambled puzzle into a state in which every face of the puzzle is a single, solid color. Some puzzles have different requirements to be considered solved, such as the Clock, for which all the dials must be moved into the 12 'o clock position.
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, or cubers. 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 and modders try to invent new forms of combination puzzles.
- 1 History
- 2 Solving methods
- 3 Competitions
- 4 World records
- 5 Lubrication
- 6 Building and Modification
- 7 Terminology
- 8 See also
- 9 Notes
- 10 External links
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 and still are 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, short for Zbigniew Zborowski, 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, and is the combination of a block-building method and a layer-by-layer method. 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 aligned with their corresponding centers. The next step solves the remaining first two layers using only left, right and top face turns, one of the advantages of ZZ. 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 user lifting both of their hands to start the time and placing both 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, 4x4x4, 5x5x5|
|One Handed Solving||3×3×3|
|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|||
|VIII||2015||Sao Paulo||July 17-19|||
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.100ths)||Person||Competition||Result Details (Min:Sec.100ths)|
|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|
|Rami Sbahi||Michigan May Madness 2014||00:01.31 / 00:01.69 / 00:02.08 / 00:02.61 / 00:01.27|
|Lucas Etter||Michigan 2014||00:01.27 / 00:01.50 / 00:02.16 / 00:01.40 / 00:03.65|
|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||00:21.97||Sebastian Weyer||Euro 2014|
|Average||00:27.17||Sebastian Weyer||Euro 2014||00:21.97 / 00:30.73 / 00:24.85 / 00:27.24 / 00:29.41|
|5×5×5||Single||00:48.42||Feliks Zemdegs||US Nationals 2014|
|Average||00:55.10||Feliks Zemdegs||Australian Nationals 2014||00:51.90 / 00:57.78 / 00:54.83 / 00:52.69 / 00:59.36|
|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||02:48.16||Feliks Zemdegs||US Nationals 2014||02:48.92 / 02:50.55 / 02:45.01|
|Megaminx||Single||00:39.57||Louis Cormier||Euro 2014|
|Average||00:45.77||Louis Cormier||Euro 2014||00:45.95 / 00:39.57 / 00:41.17 / 00:50.18 / 00:53.20|
|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||00:06.96||Bingliang Li||Guangzhou Wushan Open 2014|
|Average||00:10.21||Bingliang Li||Guangzhou Wushan Open 2014||00:09.36 / 00:11.43 / 00:06.96 / 00:09.83 / 00:12.06|
|Rubik's Clock||Single||00:05.27||Sam Zhixiao Wang||Shanghai Winter 2011|
|Average||00:06.61||Evan Liu||Oxford Open 2014||00:05.72 / 00:06.33 / 00:07.95 / 00:07.07 / 00:06.44|
|Skewb||Single||00:02.19||Brandon Harnish||Bay Area 2 2014|
|Jonatan Kłosko||Kielce Cube Attack 2014|
|Average||00:03.15||Jonatan Kłosko||Kaliska Open 2014||00:02.82 / 00:02.67 / 00:04.16 / 00:03.97 / 00:02.52|
|3×3×3: Blindfolded||Single||00:23.68||Marcin Zalewski||SLS Chorzow 2014|
|Average||00:28.43||Kaijun Lin||Guangzhou Wushan Open 2014||00:24.33 / 00:32.72 / 00:28.23|
|4×4×4: Blindfolded||Single||02:30.47||Oliver Frost||Oxford Open 2014|
|5×5×5: Blindfolded||Single||05:56.56||Oliver Frost||Welcome To Cambridge 2014|
|3×3×3: Multiple Blindfolded||Single||41/41||Marcin Kowalczyk||SLS Swierklany 2013||54:14|
|3×3×3: One-handed||Single||00:09.03||Feliks Zemdegs||Lifestyle Seasons Summer 2014|
|Average||00:11.85||Przemysław Kaleta||Masterpress Summer 2014||00:10.57 / 00:11.99 / 00:12.06 / 00:17.97 / 00:11.50|
|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||25.00||Sébastien Auroux||Velbert Easter Open 2014||27 / 27 / 21|
|Vincent Sheu||US Nationals 2014||22 / 23 / 30|
Some members of the cubing community lubricate their cubes to allow them to be manipulated faster, easier, and more reliably 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.
Building and Modification
A smaller portion of the cubing community dedicate themselves to creating ideas for new cubes, modifying existing cubes (Known as modders, or modding), and designing and producing the new puzzles themselves.
The modding community, larger than the aforementioned, takes existing puzzles and executes a process to have some desired effect. Most mods consist of simply sanding pieces down, to reduce friction, while other, more complex ones, involve cutting, shaping, and adding plastic to the puzzle to change shape and its overall mechanism and difficulty. These kinds of mods can range from simple ones such as the Cutter Cube, in which the center layer is misaligned, and the pieces are shaved down to make it seem as though it isn't, to more complex ones such as the Ghost Cube.
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, don blindfold, then solve.
- Center piece
- One of the 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 where 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.
- A commutator is a sequence of the form X.Y.X'.Y' (also represented as [X:Y] or [X,Y]) which affects only specific portions of the cube , leaving the rest untouched. This is used in Blindfolded solving and Fewest Moves Competition.
- Corner piece
- One of the 8 pieces with exactly three stickers, called a "corner" piece because a corner is exposed.
- Someone who solves any size of Rubik's Cube.
- One of the mechanically independent pieces that make up a puzzle. The cubies do not include fixed center pieces, the central axis to which they are attached, or any other internal pieces (Such as the internal edges of a 4x4 or 2x2).
- To rotate pieces' positions on the cube. e.g. a 3-cycle would make cubie set A-B-C become C-A-B.
- Acronym for Did Not Finish, used in competitions and self-timing. e.g. when a piece pop occurs and the competitor decides not to continue solving 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), by not showing up when he or she is called, or not qualifying for the remaining (usually three) 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.
- Short for Good Job, usually used to congratulate a cuber on a fast solve
- 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 sides of a puzzle, or knobs in the case of the clock.
- 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'.
- Short for One-Handed, it is the event or practice of solving a cube with one hand, left or right.
- Orientation of the Last Layer, usually used in reference to the respective step of the CFOP and ZZ methods.
- 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.
- Used in various methods, it is a technique that allows the shrinking of algorithm sets by using alternative moves. eg. Using phasing with ZZ-a will turn it into a reduced subset known as ZZ-b.
- Permutation of the Last Layer. Usually used in reference to the respective step of the CFOP and ZZ methods, in which case it would follow the OLL step.
- When, during a solve, one or more cubies come out of contact with the puzzle, usually causing the puzzle to be unstable, in which, upon turning, more pieces may become loose.
- 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.
- Winter Variation, also known as WV
- A subset of algorithms for F2L that allows the user to force all upper-face corners to be oriented correctly, or an OLL-Skip. It is used when the last F2L pair (One corner and its corresponding edge correctly positioned relative to each other) to be inserted is in the top layer, with the 3 top-layer edges oriented correctly. There are a total of 27 cases. WV has an average lower move-count than the standard OLL.
- World Record. Can also be "World Rank" when referring to the rank of a person's record in a database.
- Completing an F2L pair during the cross setup, used almost exclusively in the CFOP method.
- Considered one of the holy grails of speedcubing. It is a set of 177 algorithms (Not including mirrors and inverses) with 494 cases to recognize in order to solve the last layer in one look, also known as 1LLL, with an average move count of ~12.08. Can be used in any layer-by-layer method that ends in N-Look LL, but will only really be efficient in ZZ, as the method keeps edges oriented, whereas methods such as CFOP do not keep the edges oriented, becoming a sometimes 2LLL solve.
- "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.
- "World Rubik's Cube Championship 2015". World Cube Association. Retrieved 2014-08-04.