Hi,

I'm confused as to why there are only 21 combinations to solve PLL.

I know that all combinations can be solved by multiple PLL algorithms but I was wondering if there was a set of algorithms that will solve it in one.

I've never actually needed to use one of the algorithms during a solve but can't see why it couldn't come up.

I'm creating a code to solve this which is why I want it to be able to solve it in a single move and all combinations have to be accounted for.

Any help would be greatly appreciated.

Edit: Sorry for the lack of clarity.

I'm trying to solve this arrangement:

View attachment 10001
I can solve it using 2-look PLL but can't see how i would do it with 1 as none of the algorithms in the list seem to be able to solve it. If this can't be solved then I'm assuming there must be more but as I can't find any online.

I think there must be something I'm missing but I'm not sure what.