VLS, short for Valk Last Slot, is a subset of OLS. The VLS substep solves the last F2L pair, if the edge and corner are already paired in the last layer and can be inserted using [U]RU'R', and also skips OLL which is the third step used in the widely popular CFOP method. VLS can be used in speedsolving or FMC to decrease move count.
The rest of VLS was later generated by speedcuber Mats Valk in 2009. He had used them somewhat often in his solves, however, he did not publish them for the public and it was not commonly known that Mats used an OLS method.
A few years later in 2013, Rowe Hessler had unintentionally come up with the same idea. He generated and published all of the algorithms for the last slot method on his website, calling them "RLS" for Rowe Last Slot. Valk had later found out that Hessler had come up with the same idea and contacted him about it. They agreed to create a YouTube channel that, for a short time, made videos about VLS and HLS cases and Rowe also created a forum post introducing VLS and HLS. One year later in 2014, Rowe also created algdb pages for VLS algorithms, finally calling them "VRLS" for Valk-Rowe Last Slot, however most people still know it today by the name VLS.
There are 8 subsets under VLS. They are named after which edges are misoriented if the F2L pair is on the right and is facing towards the solver. Note that there are mirrored cases which still fall under their unmirrored subsets. These subsets includes WV, UF, UL, UB, UFUL, ULUB, UFUB, and all edges. Each of these subsets include 54 algorithms, if mirrors are counted as separate cases. It is usually recommended to first learn WV and then the rest of VLS in whatever order you choose. Learn the placement of the stickers meant to be on the top face, like with OLL.
- Move count is decreased by about 4 moves compared to normally doing the last F2L pair, then OLL.
- It requires less look ahead if implemented into solves, compared to doing the last F2L pair and OLL. So, although it only saves 4 moves, decreased look ahead can help reduce your solve times.
- Increased chance of a last layer skip.
- There are a total of 432 algorithms, including mirrors.
- Because of the first point, this means that if the solver were to learn full VLS, it would likely take at least a year if 1 algorithm was learned per day.