2-Look OLL
This OLL system is used to orient all the pieces on the last layer as described in the CFOP method, you do not need to know all 57 OLLs to use 2-look OLL (commonly abbreviated as 2LOLL), rather the system is divided up. By first orienting the edges (three cases), then orienting the corners (7 cases), orientation of all pieces on the last layer is completed.
- Step 1: Orientation of Edges (EOLL-IgnoreC) . This requires the use of one of 3 algorithms:
- Step 2: Orientation of Corners (OCLL) . Requires the use of 7 algorithms (6 excluding mirrors), to solve the following OLL cases:
The T, Bowtie and Headlights cases can be reduced to a sequence of common Sune and Anti-Sune algorithms with a U-layer move in between. This can be used to reduce the complexity of OCLL to only 4 unique algorithm blocks. The H case, in turn, can be solved by two sequential Sune algorithms (and an efficient algorithm for H eliminates redundant moves of the double-Sune sequence). Adding Anti-Sune and Pi to the Sune algorithm commonly taught as part of LBL forms an essential and efficient base for 2-look and eventually full OLL. The remaining cases can be added individually to improve performance over the two-algorithm approach to each.
If you select EO algorithms that preserve corners, it is also possible to combine the two looks into a single look (but still using two algs). This idea is known as Compound OLL.
Orientation of Corners (CO Only) and then Orientation of Edges (AKA OELL, OLL-E or OLL-ACO) is also 2LOLL, but this is less used.