# Need some help with ZBLL edge recognition.

#### Cubinwitdapizza

##### Member
So I am starting to learn ZBLL’s and I watched Chris‘ video on recognition, and I got it. But I have learned some h cases and recognition should go as follow, look at the FR corner, see where the two edges are corresponding to the corners colors, execute that case. But that doesn’t really work because you have the FR corner but it’s not the same color for every case even if you are doing from the same angle. So I’m bewildered by that and then there is the problem of which angle your doing it at If your just always looking at the FR color no matter if it’s the same or not. So if anyone could make a tutorial on ZBLL recog, then that would be awesome because there are like 2 videos about it on YouTube so it would be great.

#### xyzzy

##### Member
I watched Chris‘ video on recognition, and I got it.
Stop using Tran-style recog and go for two-sided recog: look at the two edges next to the reference corner and use that to determine the ZBLL case. (Somewhat hypocritical of me to say this, considering I mostly use a variant of Tran-style recog myself…)

But that doesn’t really work because you have the FR corner but it’s not the same color for every case even if you are doing from the same angle.
That just means that the same case looks different at two different angles. You'll just have to learn recognition for both angles. To take an extreme example, surely you know how to recognise AUF for Z perms? There are two different angles for Z perms too.

(This only affects the 2-gen H, diag H, EPLL and diag PLL subsets of ZBLL, since those are the only ones where the CLL case has nontrivial symmetry.)

#### Cubinwitdapizza

##### Member
Stop using Tran-style recog and go for two-sided recog: look at the two edges next to the reference corner and use that to determine the ZBLL case. (Somewhat hypocritical of me to say this, considering I mostly use a variant of Tran-style recog myself…)

That just means that the same case looks different at two different angles. You'll just have to learn recognition for both angles. To take an extreme example, surely you know how to recognise AUF for Z perms? There are two different angles for Z perms too.

(This only affects the 2-gen H, diag H, EPLL and diag PLL subsets of ZBLL, since those are the only ones where the CLL case has nontrivial symmetry.)
Ok i think I understand. So basically for this case R’ U2 R U R’ U’ R U R’ U R if you look at the OGY corner the edges around it are Green on R and Red on F and for this case R U R’ U R U’ R’ U R U2 R’ it’s pretty much the same except for they are swapped like a Z Perm?

#### Cubinwitdapizza

##### Member
So quick question, it’s called two sided so that means I do need to be able to recognize it from at least two different angles correct?

#### GenTheThief

##### Member
So quick question, it’s called two sided so that means I do need to be able to recognize it from at least two different angles correct?
Not quite...
Two sided refers to the number of sides that you need to recognize the case. You can actually use two sided recognition for all 4 angles, looking at two sides (plus the top) to determine the case.
You only need to be able to recognize the case from one angle, but it's generally considered better to know more than one angle.

#### PapaSmurf

##### Member
There are 2 good options: recognise the PLL using 2 sided PLL recognition (twist corners in your head), or recog the COLL, then reocg the EP relative to a certain corner which is constant for that orientation. Then once you know full ZBLL/ all of ZBLL that you want, learn recog from a U2 away, so you effectively can recog from any angle, just by tilting the cube a slight amount.

#### Cubinwitdapizza

##### Member
So everyone thinks I shouldn’t use Tran and that I should use 2 sided or twisted pll? Also if anyone could provide a link to a tutorial or make one that would be helpful because I’m still a bit confused. I see how two sided would work for like T, U, and L cases but not Pi and H.