[Help Thread] Petrus Discussion and Help thread

Are there any drawbacks to building the 2x2x2 & 2x2x3 at the same time, like in this scramble: L R2 F' U' R2 B' R2 B2 R' U' F2 R2 U' F2 U2 R' F' L2 U F L2 R D B2 R?
 
Hey there, petrus users. I'm a fairly new cuber (<2 months) and have until now been learning fridrich. I know intuitive F2l and 4LLL, and have gotten a :43 with it. When reading about other methods I was intrigued by the block building aspect of Roux, but hated the M slices needed for it. When I read about Petrus, it sounded perfect. Mostly intuitive, not many algs, lots of 2gen, block building.

So, I started learning Petrus this morning and was able to complete a solve with it amazingly quickly. Very intuitive and fun. However, because of the MANY different tutorials on Petrus out there, I'm a little unsure that I'm actually using all the right steps. It seems like I'm getting a way higher move-count on my solves than I should be. So, to make sure it's just my inexperience rather than a faulty method, I want to describe my steps and someone can confirm that they are the correct ones for Petrus.

1. Build an intuitive 2X2X2 block in as few moves as possible.
2. Expand to a 2x2x3 block intuitively.
3. Correct bad edge pairs by placing them in a specific slot and performing F' U' F
4. Complete the first two layers with only 2gen algs to preserve last layer edges.
5. Get the corners in place but not necessarily oriented with a single algorithm.
6. Use Sune as many times as needed to orient the last layer with the corners now in place.
7. Use a single algorithm as many times as needed to permute the last layer edges.

Are there more advanced or more efficent steps I could be using?
 
You can do LL in any way you want. The characteristic part of Petrus is the way it solves the F2L while orienting the LL edges. You can solve the bad edges intuitive very easily though. Look at that alg you gave (F' U' F) and see what it does to the 2 bad edges. Then compare that with for example F R2 F'.
 
1. Build an intuitive 2X2X2 block in as few moves as possible.
2. Expand to a 2x2x3 block intuitively.
3. Correct bad edge pairs by placing them in a specific slot and performing F' U' F
4. Complete the first two layers with only 2gen algs to preserve last layer edges.
5. Get the corners in place but not necessarily oriented with a single algorithm.
6. Use Sune as many times as needed to orient the last layer with the corners now in place.
7. Use a single algorithm as many times as needed to permute the last layer edges.

Are there more advanced or more efficent steps I could be using?

I recommend using OLL and PLL or any other form of 2 look last layer. I find the approach to solving the last layer on lars' site to be rather tinkery.
 
Should I look for the 2x2x2 & 2x2x3 in inspection?

Hmm. I know say that you should try to track/trace the remaining pieces while doing the 2x2x2, and eventually you'll be able to see the entire thing frome inspection.
 
Couple questions.

Do most Petrus users use 6-gen for their 2x2x2 & 2x2x3?

What method do you use for 4x4x4?

If you switched from Fridrich, do you think Petrus is better or worse for one-hand?
 
Couple questions.

Do most Petrus users use 6-gen for their 2x2x2 & 2x2x3?

What method do you use for 4x4x4?

If you switched from Fridrich, do you think Petrus is better or worse for one-hand?

Do most Petrus users use 6-gen for their 2x2x2 & 2x2x3?

I'm color neutral when it comes to petrus, so personally I do whatever is the shortest 2x2x2, or the easiest one I see, and when I extend to a 2x2x3 I use the first corner I see rather than taking time out to find the easiest.

What method do you use for 4x4x4?
Reduction + Petrus. I don't practice 4x4x4 much at all, but I average sub 2 nowadays.
 
Advanced Petrus Help

I am a new cuber and I need help with more of an advanced Petrus or last layer tutorial which would orient and twist corners all at once. There are demonstrations on http://lar5.com/cube/yMain.html but I don't understand which way corners move and how they have to be placed. If anyone knows this way better than I do, or has seen a video explaining please reply.
 
You should consider that OLL/PLL might actually be faster than COLL/EPLL for petrus.

Or even better, OLL (+CP recognition)/ PLL (with CP predicted) :)

Does this really help? I can't really imagine being much faster recognizing a PLL when I know that it's, say, a diagonal corner swap.

Obviously it won't come in handy every solve, but say for example that you know that you have diag corners, and you see a 1x2x2 block. You'll immediately know that's a V perm and won't have to look to check for headlights. If you use it every solve, things like this become very common and it really helps recognition.
 
Back
Top