A beginners guide to ROLL for PLL prediction

If you're someone who isn't super duper interested in going all in on ROLL/JOLL v2, but do want to implement the "useful" stuff from it, then you'll want to keep reading

For starters, check out Tao Yu's ROLL/JOLL generator if you haven't already. Seriously, it makes learning ROLL/JOLL a helluva lot easier

It even comes with a bookmarklet so you can literally learn ROLL/JOLL for new OLL algs in one click. Talk about learning made easy!

Anyways, back to ROLL

Truth be told, I'm actually not someone who has gone all in on ROLL/JOLL (yet) due to being busy/lazy with my free time, so I get it

ROLL for beginners is pretty much how I approach ROLL when I don't know for certain where the headlights will be for AdjCP cases, and it's something you may or may not have thought about doing yourself 

Basically, with full ROLL you learn for all 6 CP cases what to expect from your PLL (EPLL aka corners solved, DiagPLL aka no headlights, and then the 4 AdjPLL cases which have headlights either in back, front, left, or right)

However, for PLL prediction purposes, you can very easily get away with only learning 2/6 cases by simply learning which CP case corresponds to EPLL (basically just recognising the OLLCP), as well as which CP corresponds to diagCP (ENVY PLL's) 

If you were using Tao Yu's ROLL generator, you would only be learning the first 2 listed ROLL recognition schemes

For the other 4 AdjCP cases, you can easily lump them into one category since they all lead to the same PLL's. The only difference is that you can no longer predict where exactly the headlights will be

Personally I like the idea of being able to predict where the headlights are. However, where the headlights need to be for each AdjCP PLL isn't always the same so it's actually not a huge deal if you can't predict where they will be 

For my AdjCP PLL algs, headlights end up on the left in a little over 50% of the total AdjCP cases, with the remaining cases mostly being on the front or right

Because of this, I think that full ROLL probably isn’t really worth it since sometimes you won’t want headlights on left

Still, unless you’re a lefty dominant solver when it comes to your PLL, then headlights on left is going to be your largest “chunk” of AdjPLL (think Tperm, Jperm, most Gperms, Fperm etc)

Because of this, I think that the most advanced form of ROLL that is clearly worthwhile is where you know your CP for solved, diag, and the specific CP for Adj that also gives headlights on left

Using the F R U R’ U’ F’ OLL as an example, you would mostly be paying attention to when the CP case is any of the following 3

1. Matching on left, opposite on right (this gives EPLL)

2. Opposite on left, matching on right (this gives diag)

3. Opposite on left & right (this gives adj with headlights immediately on left, leaving you in the most likely scenario to be primed for Adj PLL’s)

Additionally, from this info alone you’re going to be able to naturally pick up on when headlights on right, but that doesn’t mean I recommend doing a preemptive U2 after OLL in these cases, since it could be the x R2’ D2 Aperm, or the R2’ F2 Gperm (or L2’ U’ Gperm if you’re a cool kid like me)

From there, it’s a matter of internalizing the 3 important CP cases for all 57 OLL’s, and then taking advantage from there