This Unravel Online Help is focused mainly on what the program does and how the user interacts with it. The on-line Macro help is focused mainly on the definition of macros and what they do. The approach to solving the cube is likely to be a little different for a standard cube with unmarked centres than it would be for a more complex cube with marked centres. For the unmarked case it is likely that a significant proportion of users would place about the first 40% on average without using any macros. That may drop to closer to 15% for cubes with marked centres. There is no restriction on when macros are first used, so earlier use may be preferred by some users.
The on-line help does not attempt to provide guidance on how to unscramble the portion of the cube for which macros are not provided and on how to handle some tricky unscrambling steps that may be required in conjunction with the use of some macros. Some people, especially beginners, may appreciate a small amount of help in these areas. For cubes with unmarked centres, that help is provided in the supporting document cubesolving.pdf. For cubes with marked centres that document still applies but additional help is given in markedcubesolving.pdf. Both these documents are available at the developer's website.
Anybody who can unscramble a size 4 cube should be able to unscramble cubes of larger size provided they accept a heavy time-to-solve penalty.
For a cube of size n:
Number of corner cubies | = | 8 |
Number of edge cubies | = | 12(n - 2) |
Number of centre cubies | = | 6(n - 2)2 |
Total number of cubies | = | 6(n - 1)2 + 2 |
Increase in total number of cubies for unit increase in cube size from n to n + 1 |
= | 12n - 6 |
There is a difference between the edge cubie sets for even versus odd size cubes. The central edge cubie for cubes of odd size is restricted to a 12 cubie orbit. All edge cubies for cubes of even size and all edge cubies except the central one for cubes of odd size can move to complementary positions (e.g. 2 positions each side of centre) and thus within a 24 cubie orbit.
For large size cubes the number of centre cubies becomes very dominant as indicated below.
Cube size | 4 | 8 | 16 | 32 | 64 |
Total cubies | 56 | 296 | 1352 | 5768 | 23816 |
Centre cubie proportion of total cubies (%) | 42.8 | 73.0 | 87.0 | 93.6 | 96.8 |
Because of their large number, most of the macros provided are for centre cubie placement. For cubes with unmarked centres macros are provided for all centre cubie placements except for those on the bottom layer but users may not consider their use worthwhile for the lower half of the cube. If desired, the macros can be used for bottom layer placement by moving that layer to the front and the then back again when the centre cubies have been placed.
When marked centres are used, the same macros can be used for placement of all centre cubies except those for the final layer. Instructions rather than macros are provided for the final layer for marked centres as the number of macros required would exceed the programs numerical limit. However, those instructions include macros (refer to Alignment of Marked Centre Cubies in the Upper Layer in the Macro Help for Size n Cube dialog).
The time to unscramble a cube will rise dramatically with cube size. For example there are about 24 times as many cubies to place in a size 16 cube than there are in a size 4 cube. If the average time to place a cubie were the same in both cases, that factor of 24 in time would also apply. The 24 factor is likely to be an under-estimation because the presence of a large number of cubies makes it more difficult (and time-consuming) to identify what belongs where.