Justin Czk
Member
i cant be fast enough to turn the bad into the goods.if u have any tips please tell me
i need help with petrus method step 3
- Thread starter Justin Czk
- Start date
It's all about look ahead, as you form the 2x2x3 block you should be looking to see how many bad edges you have from there is just execution like any other step. Remember that its either 2, 4, or 6 edges, you can't have an odd number. If you didn't know it existed here is the link to Petrus's web page on his method http://lar5.com/cube/. If you want you can learn the algs for each bad edges case he has them posted in the step 3 section as well as some very helpful tips it may be of more help to you.
kinch2002
Premium Member
I hope you understand what the definition of a good/bad edge is first?
With a bit of practise, recognition of where all the bad edges are should be almost immediate.
If an edge sticker matches the center piece (either F or U face if you're holding it with the block at the back) next to it, then it is obviously a good edge. Then the other ones you just need train yourself to see straight off whether they can be moved into the correct position and orientation using only F and U moves.
To actually orient them, just do moves like R U R' and L' U2 L etc. It essentially takes one bad edge up, and replaces it with another bad edge, and orients both of them by doing so. Btw, you'll always have 0, 2, 4 or 6 bad edges.
Then you should be able to solve the rest of F2L by doing y', then just <R,U> moves.
With a bit of practise, recognition of where all the bad edges are should be almost immediate.
If an edge sticker matches the center piece (either F or U face if you're holding it with the block at the back) next to it, then it is obviously a good edge. Then the other ones you just need train yourself to see straight off whether they can be moved into the correct position and orientation using only F and U moves.
To actually orient them, just do moves like R U R' and L' U2 L etc. It essentially takes one bad edge up, and replaces it with another bad edge, and orients both of them by doing so. Btw, you'll always have 0, 2, 4 or 6 bad edges.
Then you should be able to solve the rest of F2L by doing y', then just <R,U> moves.
majikat
Regular
How long have you been working on it?
like Kinch said, eventually you won't even need to think about which edges are bad, you'll just see them instantly...
and it helps a lot to really understand exactly how the short algorithms (R U R', for example) works, how it changes the orientation of the two cubes. Just do it a few times and pay a lot of attention to what is happening to those two edges. Once you realize that, you'll easily be able to alter the algorithm to fit the current needs, and not necessarily need to move the edges into place, but simply work with them where they are already.
I hope that makes sense! I guess it just takes practice, and eventually a better understanding of that step will come.
like Kinch said, eventually you won't even need to think about which edges are bad, you'll just see them instantly...
and it helps a lot to really understand exactly how the short algorithms (R U R', for example) works, how it changes the orientation of the two cubes. Just do it a few times and pay a lot of attention to what is happening to those two edges. Once you realize that, you'll easily be able to alter the algorithm to fit the current needs, and not necessarily need to move the edges into place, but simply work with them where they are already.
I hope that makes sense! I guess it just takes practice, and eventually a better understanding of that step will come.
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