Blindfold Method Classification
As of July 2011, a series of debates on the speedsolving.com forums have led to a number of people describing qualities for a potential classification system for blindfold methods. All of this input together creates the following classification system for blindfold solving methods.
3 Attribute Classification system for any blindfolded solving method:
The three attributes used to describe any blindfolded solving method in this system are: Freeness, Directness, and Cycle Length.
Freeness: Methods may be either "Free" or "Fixed". The freeness attribute describes the relative flexibility solvers use when determining which algorithm to apply in specific cases.
"Fixed" methods have a finite number options for the algorithm used to solve each and every case. Often the user will use the same algorithm for every case in every situation. In a fixed method, these algorithms are pre-planned before the solve, and the user simply recalls the correct algorithm for the given case when it is presented during a solve.
"Free" methods allow for flexibility in choosing an algorithm to handle a specific case. Users of a free method may choose an algorithm considering such factors as: their grip on the cube at the end of executing the algorithm previous, whether other pieces can be solved simultaneously with the current pieces being solved, the flow or ease of executing the algorithm. Users of a free method may have a set of pre-memorized algorithms that they will use, but will not necessarily memorize which algorithm is to be applied in each specific case.
Directness: Methods may be either "direct" or "orient first". The "orient first" attribute may sometimes be colloquially referred to as "reduction" methods.
"Direct" methods will simply solve the pieces. No indirection like solving the position and orientation of pieces in separate sub-steps.
"Orient first" methods (or "reduction") methods will separate the position and orientation of each piece as two separate pieces of information. During the solving phase pieces will first be oriented, after which they will be cycled to the correct locations.
Cycle Length: Currently, as of July 2011, blindfold methods may be either "2-cycle" or "3-cycle" methods.
"2-cycle" methods will use repeated applications of 2-cycle algorithms working from a defined buffer piece to solve the location of 1 piece at a time. Depending on the Directness attribute of the method, the orientation of the piece being cycled may also be solved at the same time. "2-cycle" methods will usually solve the location of one piece at a time, with the exception of instances where the user breaks into a new cycle at the completion of the current cycle.
"3-cycle" methods will use repeated applications of 3-cycle algorithms working from a defined buffer piece to solve the location of 2 pieces at a time. Depending on the Directness attribute of the method, the orientation of the pieces being cycled may also be solved at the same time. "3-cycle" methods will usually solve the location of two pieces at a time, with the exception of instances where the user breaks into a new cycle at the completion of the current cycle.
List of some common methods, and their classification using this system:
- 3OP (3-cycle, Orient, Permute): (either free or fixed), orient first, 3-cycle
- M2/R2: fixed, direct, 2-cycle (some users will apply this as: fixed, orient first, 2-cycle)
- TuRBo: fixed, direct, 3-cycle
- BH: fixed, direct, 3-cycle
- Free-3-cycle (Freecycle): free, direct, 3-cycle
- Freestyle: This is a hotly debated definition, but there is some consensus that freestyle methods will tend to be of two forms: free, (direct or orient first), (2-cycle or 3-cycle)
This interpretation of freestyle would suggest that the following 4 method sub-types are all "freestyle"
- free, direct, 2-cycle
- free, direct, 3-cycle
- free, orient first, 2-cycle
- free, orient first, 3-cycle
The other definition that is often used for "freestyle" is simply a method that will solve the position and orientation of pieces at the same time, using 3 cycles. In the method classification this would be all methods that are of the form: (Free or Fixed), direct, 3-cycle.
This interpretation of freestyle would suggest the following 2 method sub-types are "freestyle"
- free, direct, 3-cycle
- fixed, direct, 3-cycle
There are other definitions of "freestyle" proposed that do not match either of those mentioned here, and the debate is still ongoing as to what characteristics are necessary for a method to be classified a "freestyle" method.