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xyzzy

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Joined
Dec 24, 2015
Messages
2,876
How do I get faster at 4x4?
I use beginners.
Average 1:20 or maybe a bit less. PB 55.
I use QiYi Thunderclap mini.
I'm sub 10 on 3x3 so my 3x3 phase doesn't take too long.
Color neutral on centers.
Learn Yau and practise a lot. Also consider getting a magnetic cube—Wuque Mini M or Aosu GTS 2 M, or some custom magnetic cube if you have $$$ to burn.
 
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OLL parity probability is really high

i got 13 oll parity

1. oll parity
2. no parity
3. oll parity
4. oll parity
5. no parity
6. pll parity
7. oll and pll parity
8. oll parity
9. oll parity
10. oll parity
11. pll parity
12. no parity
13. oll parity
14. no parity
15. oll and pll parity
16. oll parity
17. no parity
18. oll and pll parity
19. oll and pll parity
20. oll parity

so, that means the probability is 13/20 (65%)
 

xyzzy

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Dec 24, 2015
Messages
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Okay kids, it's time for a crash course in statistics.

Let's say we have a completely fair coin. 50% heads, 50% tails, every flip is independent. (For technical reasons, actual physical coins are very much not fair and you can train yourself to flip a coin to land the same way every time. So let's say we use a computer instead, but still call it a "coin" for expository purposes.)

If you flip it once, there's a 50% chance of getting 0 heads, and a 50% chance of getting 1 head. (Duh, this is obvious.)

If you flip it twice, there's a 25% chance of getting 0 heads, a 50% chance of getting 1 head, and a 25% chance of getting 2 heads. (Think about this for a while. It'll make the rest of it obvious.)

If you flip it thrice, there's a 12.5% chance of getting 0, 37.5% chance of getting 1, 37.5% chance of getting 2, and 12.5% chance of getting 3.

If you flip it four times, the distribution becomes 6.25% : 25% : 37.5% : 25% : 6.25%.

Even if we started with a completely fair coin, there's only a 37.5% chance that flipping it four times will give you the "expected" number of heads. If I hadn't told you ahead of time that the coin was fair, you flip it four times and you see something other than 2 heads + 2 tails, should you immediately conclude that the coin is biased? If you do, that means that your "this coin is biased" decision process is wrong 62.5% of the time when given a fair coin.

Now replace coin flips by 4×4×4 solves, heads with no OLL parity and tails with OLL parity, and observe that your original statement really didn't make a lot of sense.

Now consider the following. I tell you the coin is fair, and let's say you usually think I'm a trustworthy person, but you flip it a thousand times and every single time it shows up heads. The probability of this happening with a fair coin is 1/2^1000, roughly equal to a tenth of a googol-th of a googol-th of a googol-th. This is a number so tiny, so close to zero, that it completely defies human intuition.

If you think I'm absolutely infallible, then the only reasonable conclusion is that the coin is fair. After all, any sequence of 1000 flips has the same 1/2^1000 probability of showing up—it just so happened that you got all heads.

However, if you think that there's even a 0.000001% chance that I gave you a dud coin that has heads on both sides, the probabilities change completely. (For simplicity, assume the two possibilities are dud coin (100% heads) and fair coin (50% heads, 50% tails).) You've already gotten 1000 heads on 1000 flips. A quick calculation:
P (it's a dud coin | 1000 heads) = P(it's a dud coin and 1000 heads) / P(1000 heads) {by the definition of conditional probability}
= 0.000001% / [P(it's a dud coin and 1000 heads) + P(it's a fair coin and 1000 heads)] {splitting into cases}
= 0.000001% / [0.000001% + 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001%]
= 99.999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999%

It's overwhelmingly likely that the coin I gave you was a dud, if you have even the slightest suspicion that I'm not telling you the truth. Of course, to do meta-level reasoning like this, you need to be able to do object-level reasoning first, so study in school and pay attention during your maths/stats classes.
 
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Duncan Bannon

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Hello!

I have a goal to go from Averaging about 1:05 -1:10, to have an average of 12 sub 50. Big goal, yes I'm aware.

Heres information about me:

Average- 1:05 to 1:10, I use Yau and average about 15 seconds on 3x3.

F2C- 5.54
F3E- 10.94
L4C- 9.62
Last Cross Edge- 3.32
Edge Pairing- 16.38
3x3 stage- 21.47

F2C- Trying to influence second center when doing first some now. Am Yellow-White CN on 4x4.

F3E- None

L4C- I use solely half centers

Last cross edge- I rotate then solve this edge every time (never do this while holding white and yellow on L and R sides)

Edge Paring- During the first "3" of 3-2-3 I rotate to insert each edge half

3x3 Stage- I do always do white cross (I'm CN on 3x3), but I could switch that. I don't use any fancy things with OLL or PLL parity to get better cases.

Thank you!

Edit- Might be faster than I thought. Got a 1:02 Ao12.
 
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xyzzy

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Joined
Dec 24, 2015
Messages
2,876
F2C- 5.54
F3E- 10.94
L4C- 9.62
Last Cross Edge- 3.32
Edge Pairing- 16.38
3x3 stage- 21.47
If my splits are representative, you need to work on everything, including your 333 stage.

I use my own method for F3E+L4C, but basically in F3E try to constantly look for edge pieces you need. As you form a cross dedge and insert it, 90% of the time there'll be a useful piece that's directly visible. Exploit that to make F3E flow smoothly. (I don't have any tips regarding L4C because that's also a step I'm weak at when I try to do conventional Yau solves.)

Last cross dedge: Track the two pieces needed while finishing centres.

Rest of edge pairing: Rotating for each piece is fine (even if it's not optimal in the long run). Track the pieces you need as you go along. Take note of which piece will end the current cycle, so that when you see it, you know you have a weird cycle case (instead of wasting 2+ seconds trying to look for a piece in the top layer when it's stuck in another slot). I don't personally know what the best ways of dealing with weird cycle cases are, but J Perm has a video on that.

If you finish with an F2L dedge in edge pairing, make use of that when looking ahead (because it's already visible and you just need to look for the corner).

333: TURN FASTER Figure out why you're so much slower here than on a normal 333 solve, then fix whatever needs fixing. Drill the parity algs. Learn the three main PLL parity algs and use the fastest one for you. (Note that 2R2 can be executed as r2 R2 or R2 r2.)

2R2 U2 2R2 u2 2R2 u2
[u2 r2 U2 : 2R2]
[r2 F2 U2 : 2R2]

Learn COLL. Learn adj EPLL and W perm algs. (The best algs for adj depend on which PLL parity alg is the fastest for you, but for W perm, cancelling U perm into the first alg above looks like the best.) On big cubes, COLL+EPLL is pretty good since the non-parity EPLL algs are all RU 2-gen-able (although you still should use MU for H perm on 4×4×4) and the parity EPLL algs are mostly nice.

This step should take 2-3 seconds longer than your normal 333 solves; parity adds ~3 seconds, the lower turning speed on a big cube adds ~1 second, and having the cross solved saves ~1-2 seconds.
 
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fiona

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Jan 2, 2019
Messages
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PLEASE HELP IM ALWAYS STUCK WITH 1 OR 2 CORNERS ON THE LAST LATER OF THE 4X4 CUBE - I CAN ORIENTATE THE LAST 4 CORNERS BUT THERES ALWAYS ONE THAT WONT ORINTATE I USE THE R D R L RIGHT DOWN RIGHT INVERTED AND RIGHT UP LEFT INVERTED BUT THERES ALWAYS 1 THAT WILL NOT ORIENTATE WHAT IS THE LAST ALGORITHANM FOR 4 CORRECT CORINTATED CORNERS PLEASSE HELP IM MISSING SOMETHING BUT I CANT FIGURE
 

obelisk477

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PLEASE HELP IM ALWAYS STUCK WITH 1 OR 2 CORNERS ON THE LAST LATER OF THE 4X4 CUBE - I CAN ORIENTATE THE LAST 4 CORNERS BUT THERES ALWAYS ONE THAT WONT ORINTATE I USE THE R D R L RIGHT DOWN RIGHT INVERTED AND RIGHT UP LEFT INVERTED BUT THERES ALWAYS 1 THAT WILL NOT ORIENTATE WHAT IS THE LAST ALGORITHANM FOR 4 CORRECT CORINTATED CORNERS PLEASSE HELP IM MISSING SOMETHING BUT I CANT FIGURE

1) press caps lock button
2) manually twist the unsolved corner with your hand. you must have twisted without realizing it
 

fiona

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Jan 2, 2019
Messages
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no ive done the twisting theres always that 1 layer of pieces thats wont orientate in the right position there in the right place but 1 or 2 just wont orientate i look under the cube turn it over and theres always pieces out of place could there be a some of the tiles in the wrong places as my cube came apart twice about 6 pieces and i put them back in but dont know if i put the correct ones in there place , would this make a difference?
 

xyzzy

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Dec 24, 2015
Messages
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no ive done the twisting theres always that 1 layer of pieces thats wont orientate in the right position there in the right place but 1 or 2 just wont orientate i look under the cube turn it over and theres always pieces out of place could there be a some of the tiles in the wrong places as my cube came apart twice about 6 pieces and i put them back in but dont know if i put the correct ones in there place , would this make a difference?
If that's the case, it's very likely that your cube has a messed up colour scheme on some pieces now. If you provide pictures, we might be able to tell which tiles you need to swap to get it back to a solvable state.

(Note that a corner piece should never have two of the same colour.)
 

fiona

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Jan 2, 2019
Messages
3
If that's the case, it's very likely that your cube has a messed up colour scheme on some pieces now. If you provide pictures, we might be able to tell which tiles you need to swap to get it back to a solvable state.

(Note that a corner piece should never have two of the same colour.)
0.jpg1.jpg3.jpg4.jpg

hi there all the 4 squares are in the right position - can you advise me what to do now as i keep doing the right down right inverted think its just 4 moves repeated but it never solves the cube always leaves 1 or 2 unsolved and the underneath all messed up

can you tell from the pictures if theres any thing wrong with the cube or the corners and can you figure out a algorithim for the corners please
 

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Mike Hughey

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From the pictures you have there, one of the corners has been twisted in place. If the cube is still in the state of the photos shown there, if you can twist the corner on the yellow side with the red on top so that yellow is on top (so that that particular cubie is solved), the remaining two corners should be able to be solved normally.

It will depend on what type of cube you have as to how hard it will be to twist the corner. With most modern 4x4x4s, it is not too difficult to simply twist the corner in place - it requires a bit of force but it can be done. With some older 4x4x4s, you might have to take some other pieces out of the cube (the edges next to it) in order to twist the corner. Be careful not to put too much force on it; it is certainly possible to break a corner cubie that way - I have done it before on one of my 4x4x4s.
 

The Cubix

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Dec 13, 2018
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Hi! I need help with the 4x4x4. My average is 1:40 minutes. I use the Yau method but I first do all centers and after that, I start cross edges and 3-2-3 edge pairing. My centers are taking 20 seconds, the edge pairing 50 seconds and the 3x3x3 step + parity 30 seconds on average. How could I get faster? My goal is a sub 1:20 average.
 

xyzzy

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Dec 24, 2015
Messages
2,876
I use the Yau method but I first do all centers and after that, I start cross edges
This is like the worst of both worlds in combining Yau with reduction, so stop doing this. (I just did a bunch of solves to check, and I got a 51 average with Yau, 57 with redux, and 1:01 with this hybrid method.)

Beyond that, just practise a lot.
 
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