When you inspect the cube before you solve...

[pcwiz]

Hi Everybody!

I have another question for you speedcubers who can get sub 30 seconds. When you inspect the cube, how do you plan out your cross? I mean you look at where all the edge pieces are, and do you plan an algorithm? I mean do you make an algorithm just from trying to solve the cross? Or do you just do a series of moves and watch how each piece goes? I mean that's what I do and I get a 10 second average (stinks ). I see professionals they do the cross it looks like they just do it in like 2 seconds without looking at the cube seriously. So do you guys memorize the moves that go, knowing ahead where each edge piece is going to go, or do you guys look as you solve?

 

[Eliawz]

i look for 1 piece of the cross ( i do white cross) lets take an example the white and red one if i see that it can be placed in 1 move i check that if the white blue piece or white green piece can also be placed in 1 move if either of those pieces cant be moved in 1 moves to the right spot then i place it with the same time with the red/w one.try this do this alg on your cube
R F' U' F' thats the case that im talking about so it can be placed by F U F R' .anyway you could wait for better instructions for this since my englsh is bad and im only around sub 30. you can try this link http://cubefreak.net/cross.html . For the 15 secs inspection time i memrize the mive sequence ive made in my head for doing the cross, you can practice that by trying to do the cross without lookin after you have inspected the cube.

 

[pcwiz]

Yes I've looked at that website before.. and the one on Dan's Cubestation read everyword

So when you memorize the sequence, do you look ahead and see what the cube will look like after every move? So you apply those steps without even thinking about it? So you think about during inspection time and just apply it when you do the cross? How fast do you do the cross anyway?

 

[Rosetti]

I'm a noobie, but during my inspection (bearing in mind, I use Petrus)

I first find 3 pieces I need, then figure out how to put them together, and try to also consider what effect it will have on other pieces I'm watching.

I usually try to find the other pieces whilst moving around the ones I already know. But using my pre-inspection and looking ahead is what I'm working on most right now.

To translate into cross making - I'd find say, 3 edges of the cross, and work out how to put the first one in, I would then also be trying to think what would happen to the other edges as I put that first one in. Whilst doing this for the 3 edges I spotted, I would have found the last edge, and put that in.

Also, just a quick question to the advanced cubers, do you use your pre-inspection primarily for building your Cross/2x2x2 block? Or are you also thinking about the next steps?

 

[Crzyazn]

I locate each piece (easy)
Make a mental note of how they are relative to each other (medium)
Intuitively figure out an easy to remember set of opening moves for the cross (medium hard)

My opening moves usually put one or two pieces correctly oriented and the others in very quick/easy positions to solve

 

[pcwiz]

Okay now I know the steps, but how long does it take you guys (average) to solve the cross?

 

[pete]

So when you memorize the sequence, do you look ahead and see what the cube will look like after every move?

you don't need to memorize how the entire cube is going to look after each move,
just try to think where each of the individual pieces is going to be after each move.
if you feel it's hard to follow all 4 edges of the cross, then initially follow just 2,
later with practice you'll learn how to follow 3 and eventually all 4.

So you apply those steps without even thinking about it? So you think about during inspection time and just apply it when you do the cross? How fast do you do the cross anyway?

yes, with practice this will become almost natural, you apply your pre-planned moves
without thinking about it, even without looking and that gives you more freedom
to think about your next strategy after the cross is completed.

I only started recently after 25 years without cube and I cannot yet pre-plan
all 4 edges of the cross but I'm almost there. I can do first 3 edges without thinking
and while I'm busy moving those 3 edges in place I try to follow the
4th piece so that I know exactly where it is after I'm done with those first 3.

I do the cross in 7 moves on average and it takes me 3.5 seconds on average (that is comparatively slow)

 

[n00bcubix]

This si what i do, I just find the cross pieces and try to find the fastest execution algorithm to finish the cross. Since i know the color scheme, idon't bother looking around at the colors. After i do that, i try to find a pair that would be easy to slot in after the cross. (Ex: R U R') Then since i know what im doing with the cross and perhaps another pair, i would look for another pair during the R U R' trigger and the cross. If I find it, I use intutive and I know what I'm doing so I try to find another pair. And so on.

 

[pcharles93]

Each cuber has their own way of doing their cross, but the constant is there are 2 goals for Fridrich users.
1) Make it in the fewest moves required. This should be easy if you understand how the cube works
2)Preserve corner/edge pairs. This doesn't happen all the time and sometimes I pair one up intentionally. I lose like 2 seconds on the cross but I save about 5 or 6 on the first pair.

Just play around with the cube and experiment how each turn affects edges.

 

[TimMc]

I generally do the following:
- Find the 4 edges
- Determine the fewest moves to complete the Cross
- Avoid breaking up an F2L pairs by extending a 2x2 block (if any)

When determining the fewest moves I look at:
- The orientation of every edge with respect to the faces
- The location of every edge
- The effects one move will have on the orientation on any edge

I don't spend much time inspecting. Just enough to memorize the location and orientation and then I just instinctively do what comes naturally.

If I have to think too hard about executing the fewest moves I'll end up wasting time. Sometimes it's more efficient to select an inefficient route and execute it faster

Tim.

 

[pcwiz]

Thank for the information! This helped me a lot!
By the way, you said you don't spend a lot of time inspecting. How much time do you inspect, and since you have 15 seconds to inspect, shouldn't you use all of the time you are given?

 

[Feanaro]

I personally look for all the 4 white pieces and see which ones are already on the bottom. Then I try to use the least amount of moves (if convieniant) to make the cross. I don't use any algorithms. It just takes practice. I would put the white pieces on the top and move them to the bottom for a long time, I only just recently (6 months ago) started doing them on the bottom. Again it just takes a little practice.

 

[fanwuq]

I don't understand. Doing the cross has always been easy for me. What I can't do is do it super fast. I get about 2-5 seconds while attempting to look ahead a little. I'm amazing at the records on ryanheise.com where the fastest people do the cross in less than one second and still never stops during a solve. I just do what I can see of the cross and it is really inconsistent. Sometimes I can see extend cross on a difficult case, other times I can only see 3 edges. At the times I can't see the whole cross, usually I go really slow because There are f2l pairs that I don't want to break. So I kinda do pseudo-Petrus. And insert the last cross piece at the end of f2l using M' U M .

I would appreciated it if anyone can tell me a better way of handling the situation when there are F2L pairs at the beginning that are broken if you finish cross.

 

[Lofty]

I have a bit of trouble during inspection too... I've solved the cross enough times that I can see that almost instantly. But when I try to see more than that I can't... I'd ask for help but I think my answer is just practice I really wish I could see Cross and first pair... or 2x2x2 plus some of 2x2x3...

 

[coopersacatfilms]

if you can set up opposites where you don't align right away you can set up the opposites and then do a D or D2 or D' u or u2 or u' just practice and it will be come pretty intuitive.