# Problem with Corner Twists



## Huntermagic (Jan 3, 2014)

It is clear that the WCA rules for puzzle defect is made mainly for situation like pops in the first place. Since corner twists tend to occur more easily with some of the new cubes, and possibly unoticed because you can still turn normally with a corner twisted. I think corner twist is still an issue that needed to be addressed better in the WCA regulation. 

From the section of puzzle defect:
--5a) Examples of puzzle defects include: popped parts, pieces twisted in place, and detached screws/caps/stickers.
--5b) If a puzzle defect occurs during an attempt, the competitor may choose to either repair the defect and continue the attempt, or to stop the attempt.
--5b2) Any repair to a puzzle must not give the competitor any advantage in solving the puzzle. Penalty: disqualification of the attempt (DNF).
--5b3c) If the puzzle is unsolvable, and can be made solvable by rotating a single corner piece, the competitor may correct the corner piece by twisting it in place without disassembling the puzzle.

My question here is: 
1. If a corner twist occurred without the attention of both the judge and the competitor, and the competitor found out the problem when he got to a later stage of solving such as OLL, in which the twist was more obviously recognized. Should the penalty be given because it violated rule 5b?
2. Should a person is allowed to fix the twist at the OLL, in the end, or whenever he/she recognized it, which corner should he twist so rule 5b2 is complied with. (recognizing the initially twisted corner is not possible here)

Please tell me what you people think and how you would deal with such situation in a competition.


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## Dene (Jan 3, 2014)

Actually, the regulations were worded in this way, pretty much to explicitly deal with corner twists. The answers to your questions are simple:

1. It is not possible to "violate" 5b, and there is certainly no penalty for it. Just repair the puzzle whenever you want; but I would recommend doing it asap, whatever the defect, as the longer you put it off the more it will negatively impact your solve (e.g. if you put off a corner twist until the end of the solve, you cannot repair the corner that is out of place, as that would violate 5b2, so you would be forced back to OLL (method dependent, of course)). This leads to your next question...
2. This depends on the situation of the solve and is a judgement call, but you cannot advance the solve by repairing the defect, so for example, you cannot twist a corner as the last move to solve OLL; you must instead twist another corner to create an OLL case with two twisted corners.


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## Huntermagic (Jan 3, 2014)

So if a twist is spotted by the judge, is the judge required to stop the competitor at the moment and ask him to choose either repair and continue or to stop the attempt?


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## MaeLSTRoM (Jan 3, 2014)

Dene said:


> 2. This depends on the situation of the solve and is a judgement call, but you cannot advance the solve by repairing the defect, so for example, you cannot twist a corner as the last move to solve OLL; you must instead twist another corner to create an OLL case with two twisted corners.



This is surely a border case, because what if you were going to get an OLL skip but have only 1 corner twisted, are you really expected to intentionally unsolve the cube to fix the corner? If so, please tell me where you got this from as it doesn't say that in the regulations. At least not directly.



Huntermagic said:


> So if a twist is spotted by the judge, is the judge required to stop the competitor at the moment and ask him to choose either repair and continue or to stop the attempt?



I think you misunderstand. You make the choice yourself, you don't need the judge to ask you, it's entirely your own choice, so you would spot the twist, and you can continue up to whatever point and then twist the corner to correct the state, or just DNF when you see the twist.


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## Goosly (Jan 3, 2014)

MaeLSTRoM said:


> This is surely a border case, because what if you were going to get an OLL skip but have only 1 corner twisted, are you really expected to intentionally unsolve the cube to fix the corner? If so, please tell me where you got this from as it doesn't say that in the regulations. At least not directly.



Yes. Rule 5b2. You accidentally twisted a corner. It might have been an OLL-case with 2 twisted corners, it might have been an OLL-skip. You'll never know. But you are required to not take an advantage from this, and thus you must flip a different corner.

_"5b2) Any repair to a puzzle must not give the competitor any advantage in solving the puzzle. Penalty: disqualification of the attempt (DNF)."_


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## MaeLSTRoM (Jan 3, 2014)

Goosly said:


> Yes. Rule 5b2. You accidentally twisted a corner. It might have been an OLL-case with 2 twisted corners, it might have been an OLL-skip. You'll never know. But you are required to not take an advantage from this, and thus you must flip a different corner.
> 
> _"5b2) Any repair to a puzzle must not give the competitor any advantage in solving the puzzle. Penalty: disqualification of the attempt (DNF)."_



OK so assume you get an OLL case with 3 twisted corners, such as sune, but one of them is twisted incorrectly. Normally you would do a sune, then have 1 corner twisted, and then you have to unorient another corner and then solve that OLL as well? Surely that's not giving any advantage, just stacking another disadvantage.


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## Goosly (Jan 3, 2014)

Hmmm, I guess you can twist the 1 flipped corner back then. Dunno actually  I don't think any judge will give you a DNF for doing that.


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## Dene (Jan 3, 2014)

MaeLSTRoM said:


> OK so assume you get an OLL case with 3 twisted corners, such as sune, but one of them is twisted incorrectly. Normally you would do a sune, then have 1 corner twisted, and then you have to unorient another corner and then solve that OLL as well? Surely that's not giving any advantage, just stacking another disadvantage.



This is why I advised fixing the issue asap. In my opinion, in your example I would say the correct action to take is to twist one of the oriented corners to make another OLL case, even after doing a sune first.

In practise I possibly wouldn't rule against it though, because the solve would already be ruined.


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## Robert-Y (Jan 3, 2014)

You don't even know which corner was twisted. What if the competitor untwisted the correct corner and got an OLL skip? Will you tell them that that is forbidden?


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## Dene (Jan 3, 2014)

Robert-Y said:


> You don't even know which corner was twisted. What if the competitor untwisted the correct corner and got an OLL skip? Will you tell them that that is forbidden?



I don't understand the scenario exactly. Could you elaborate? I have been very clear about my opinion in how to interpret the rules in a case where OLL is "finished" except for one twisted corner.


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## DavidCip86 (Jan 4, 2014)

What if you see the corner twist on the oll, and depending on which way you twist the corner, you could get a better case? (dunno if I explained very well lol)


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## Methuselah96 (Jan 4, 2014)

DavidCip86 said:


> What if you see the corner twist on the oll, and depending on which way you twist the corner, you could get a better case? (dunno if I explained very well lol)





Dene said:


> This depends on the situation of the solve and is a judgement call, but you cannot advance the solve by repairing the defect, so for example, you cannot twist a corner as the last move to solve OLL; you must instead twist another corner to create an OLL case with two twisted corners.



Please try to read the other posts of the thread carefully.


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## DavidCip86 (Jan 4, 2014)

Methuselah96 said:


> Please try to read the other posts of the thread carefully.


I'm not talking about skipping oll, I mean just making a better case compared to a worse case. 

For example you could have two unoriented corners, but it is not a valid case. If you twist an oriented corner, you could get sune. If you twisted an unoriented corner, you'd get something worse than sune. Does it matter what corner you twist?


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## Dene (Jan 4, 2014)

DavidCip86 said:


> For example you could have two unoriented corners, but it is not a valid case. If you twist an oriented corner, you could get sune. If you twisted an unoriented corner, you'd get something worse than sune. Does it matter what corner you twist?



The case which you deem to be "better" or "worse" is a subjective matter, and doesn't advance the solve in theory, so in this case it doesn't matter.


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## DavidCip86 (Jan 4, 2014)

Dene said:


> The case which you deem to be "better" or "worse" is a subjective matter, and doesn't advance the solve in theory, so in this case it doesn't matter.



Ok thanks :-D


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## Huntermagic (Jan 4, 2014)

MaeLSTRoM said:


> I think you misunderstand. You make the choice yourself, you don't need the judge to ask you, it's entirely your own choice, so you would spot the twist, and you can continue up to whatever point and then twist the corner to correct the state, or just DNF when you see the twist.



This is the main problem here. I believe this is the issue that needs clarification before discussing which corner to twist and whether it gives a solving advantage to the competitor. In the case when the twist is spotted right away by at least the judge, according to rule 5b, I don't see the reason how the competitor can "spot the twist, and continue up to whatever point and then twist the corner to correct the state" since the rule only gave the competitor 2 choices when the defect occurs, either to fix, or DNF. I believe cases with unoticed twists should be discussed separately. 

--5b) If a puzzle defect occurs during an attempt, the competitor may choose to either repair the defect and continue the attempt, or to stop the attempt.


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## Lchu613 (Jan 4, 2014)

Dene said:


> This is why I advised fixing the issue asap. In my opinion, in your example I would say the correct action to take is to twist one of the oriented corners to make another OLL case, even after doing a sune first.



I would re-orient the corner before doing sune and save myself a bit of trouble. 

I'm guessing you're referring to doing sune before noticing the corner is twisted?


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## Angel Lim (Jan 4, 2014)

What happens if during a 3bld you exe perfectly but you end with one corner twist (either by the scrambler or unknowingly by you). Is this a DNF?


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## Dene (Jan 4, 2014)

Lchu613 said:


> I'm guessing you're referring to doing sune before noticing the corner is twisted?



Indeed I am.



Angel Lim said:


> What happens if during a 3bld you exe perfectly but you end with one corner twist (either by the scrambler or unknowingly by you). Is this a DNF?



Yes.


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## Robert-Y (Jan 4, 2014)

Dene said:


> I don't understand the scenario exactly. Could you elaborate? I have been very clear about my opinion in how to interpret the rules in a case where OLL is "finished" except for one twisted corner.



Ok here's an example. On a solved cube, twist the UFR corner. Do R U R'. Now let's say I'm about to finish F2L, so I do R U' R'. Now I think "Oh look, I accidentally twisted a corner. I guess I'll twist the UFR corner and get a LL skip." This is the correct corner to correct. But you're saying I should twist a different corner instead? Are you saying this is not allowed?

You probably wouldn't even be able to tell me which corner I accidentally twisted.

EDIT: Here's another example. Twist the UFR corner and do an antisune on a solved cube. Let's say I'm about to do OLL and upon inspecting the LL corners, I realise that one of the corners need twisting. So I twist the UFR corner. Now I do a sune and my cube is solved. I *know* when doing a sune will give me a PLL skip. However many cubers don't know this and may obtain an advantage by chance.

However:

--5b2) Any repair to a puzzle must not give the competitor any advantage in solving the puzzle. Penalty: disqualification of the attempt (DNF).

You may say that an "advantage" was given, but by accident.

But:

- 5b3c) If the puzzle is unsolvable, and can be made solvable by rotating a single corner piece, the competitor may correct the corner piece by twisting it in place without disassembling the puzzle.


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## Kirjava (Jan 4, 2014)

Dene said:


> I would recommend doing it asap, whatever the defect, as the longer you put it off the more it will negatively impact your solve



Pfft. Leaving it until then end could allow you to skip doing a ZBLL two corner twist by just letting you twist a corner, and the judge can't prove it wasn't an LL skip because he wasn't tracking all corner orientations!


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## Dene (Jan 4, 2014)

Robert-Y said:


> Ok here's an example. On a solved cube, twist the UFR corner. Do R U R'. Now let's say I'm about to finish F2L, so I do R U' R'. Now I think "Oh look, I accidentally twisted a corner. I guess I'll twist the UFR corner and get a LL skip." This is the correct corner to correct. But you're saying I should twist a different corner instead? Are you saying this is not allowed?
> 
> You probably wouldn't even be able to tell me which corner I accidentally twisted.



The problem, as you mention, is that we don't know which corner is defective. So in this case, unless you are sure it was that corner which twisted (let's say you felt it as you were doing a previous move), the correct interpretation of the rules is to twist a different corner to avoid "advancing" the solve, to what is the best of our knowledge. This is why I strongly recommending fixing a corner twist asap, or else it could potentially *disadvantage* yourself (by not being able to get a skip).



Robert-Y said:


> Here's another example. Twist the UFR corner and do an antisune on a solved cube. Let's say I'm about to do OLL and upon inspecting the LL corners, I realise that one of the corners need twisting. So I twist the UFR corner. Now I do a sune and my cube is solved. I *know* when doing a sune will give me a PLL skip. However many cubers don't know this and may obtain an advantage by chance.



This is an interesting case, and this is where the regulations get into grey area. Personally I wouldn't recognise that the sune would lead into a PLL skip (I don't know any cases like this), so if I were judge I couldn't tell if you deliberately "advanced" the solve or not. I think the best interpretation of the rules is to look at the solve in the context of the immediate, and not the future. As long as you don't give yourself an OLL skip while twisting the corner during OLL, that should be good enough.

Of course, it's difficult when we start talking about other methods, and the regulations need to stay method-independent. What I mean by this is I wouldn't be able to tell if a Roux user advanced their solve or not, so in practise there are many difficulties. I'm just trying to provide the best interpretation of the rules as I can, but in reality if I saw something in competition I would take it as it came. For example, if I saw someone get to OLL and do an algorithm, and they were left with a twisted corner, I'd accept it if they just twisted that corner back into place. This is again an ambiguous case given the regulations, and I think discretion comes into play here. Ultimately, having a twisted corner sucks so it's punishment enough


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## Robert-Y (Jan 4, 2014)

But doesn't

- 5b3c) If the puzzle is unsolvable, and can be made solvable by rotating a single corner piece, the competitor may correct the corner piece by twisting it in place without disassembling the puzzle.

overrule this?

Most of the time I do it, it is by accident and I cannot immediately tell unless I reach the last layer of the puzzle.

EDIT:



Dene said:


> The problem, as you mention, is that we don't know which corner is defective. So in this case, unless you are sure it was that corner which twisted (let's say you felt it as you were doing a previous move), the correct interpretation of the rules is to twist a different corner to avoid "advancing" the solve, to what is the best of our knowledge.



Please tell how you have interpreted this from article 5: https://www.worldcubeassociation.org/regulations/#article-5-puzzle-defects

EDIT2: Sorry, I've actually reading this part: "5b3) Permitted repairs:" has "exceptions". I guess it changes things slightly.


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## Dene (Jan 4, 2014)

I'm completely confused by your entire post. 

"but doesn't" is in response to what?

5a Examples of puzzle defects include: ... pieces twisted in place

5b3c If the puzzle is unsolvable, and can be made solvable by rotating a single corner piece, the competitor may correct the corner piece by twisting it in place without disassembling the puzzle.


Where is the confusion? I'm confused >.<


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## Robert-Y (Jan 4, 2014)

I take that back, because the whole time, I was misreading the permitted repairs as exceptions to overrule 5b3c.

What I was trying to say earlier was that there could be many instances in a solve in which the competitor twisted a corner X by accident but neither the competitor nor the judge will realise this until later on in the solve. Assuming that the competitor uses CFOP and reaches OLL, he may get an OLL in which he only needs to twist X to solve. But as mentioned in the case, neither the competitor nor the judge know which corner was originally twisted. Yet the right action is to disqualify the competitor if he were to untwist X? Is that really fair?


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## Dene (Jan 4, 2014)

Robert-Y said:


> What I was trying to say earlier was that there could be many instances in a solve in which the competitor twisted a corner X by accident but neither the competitor nor the judge will realise this until later on in the solve. Assuming that the competitor uses CFOP and reaches OLL, he may get an OLL in which he only needs to twist X to solve. But as mentioned in the case, neither the competitor nor the judge know which corner was originally twisted. Yet the right action is to disqualify the competitor if he were to untwist X? Is that really fair?



When you put it in that way, I would say it isn't fair. But the "fairness" factor no longer exists in practise, as you cannot possibly know which corner is X. I'm not sure if I've stated that clearly; do you get what I mean?


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## Robert-Y (Jan 4, 2014)

Not really sorry :S


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## Methuselah96 (Jan 27, 2014)

Sorry to bring up an old topic, but what if the competitor knows that he twisted a corner in the middle of the last F2L pair and he knows which corner he twisted. It happens that it would have been an OLL skip. If he twists it back, he is definitely not getting any advantage in solving the puzzle. It would only be an advantage if he didn't know what corner he twisted.

Also, is a judge really expected to be able to follow the way the person is solving the cube and whether it advances the solve? As Dene pointed out earlier, she would have no clue if a person was getting an advantage in a method other than CFOP. I believe one of the main points of the WCA judging system is that anyone can judge. people who don't solve the cube don't have a clue what's going on. This would mean that people who have a non-cuber judge could twist a corner to solve OLL and the judge wouldn't know.


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## Angel Lim (Jan 27, 2014)

I'm paranoid when I do BLD that I'm going to corner twist when turning too fast.

In the event that this happens in comp, I suppose I'll have to complete the entire solve and then just guess which way my buffer was twisted :/


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## Dene (Jan 27, 2014)

Angel Lim said:


> I'm paranoid when I do BLD that I'm going to corner twist when turning too fast.
> 
> In the event that this happens in comp, I suppose I'll have to complete the entire solve and then just guess which way my buffer was twisted :/



Or you could just use a cube that doesn't get corner twists.........


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## kcl (Jan 28, 2014)

Dene said:


> Or you could just use a cube that doesn't get corner twists.........



Sure, because using rubiks brands for BLD Is perfect.


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## TMOY (Jan 28, 2014)

Angel Lim said:


> I'm paranoid when I do BLD that I'm going to corner twist when turning too fast.
> 
> In the event that this happens in comp, I suppose I'll have to complete the entire solve and then just guess which way my buffer was twisted :/



And you'll get a DNF because of two twisted corners: the one which twisted initially and your buffer 

Most of the time, when a corner twists during BLD you can feel which one is twisting and in which direction. Just twist it back.


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## Dene (Jan 28, 2014)

kclejeune said:


> Sure, because using rubiks brands for BLD Is perfect.



Or just tighten a guhong a bit.


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## Methuselah96 (Jan 29, 2014)

Methuselah96 said:


> Sorry to bring up an old topic, but what if the competitor knows that he twisted a corner in the middle of the last F2L pair and he knows which corner he twisted. It happens that it would have been an OLL skip. If he twists it back, he is definitely not getting any advantage in solving the puzzle. It would only be an advantage if he didn't know what corner he twisted.
> 
> Also, is a judge really expected to be able to follow the way the person is solving the cube and whether it advances the solve? As Dene pointed out earlier, she would have no clue if a person was getting an advantage in a method other than CFOP. I believe one of the main points of the WCA judging system is that anyone can judge. people who don't solve the cube don't have a clue what's going on. This would mean that people who have a non-cuber judge could twist a corner to solve OLL and the judge wouldn't know.



Can somebody answer this? I don't feel like the regulations on this are very clear.


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## Sa967St (Jan 29, 2014)

Methuselah96 said:


> Methuselah96 said:
> 
> 
> > Also, is a judge really expected to be able to follow the way the person is solving the cube and whether it advances the solve? As Dene pointed out earlier, she would have no clue if a person was getting an advantage in a method other than CFOP. I believe one of the main points of the WCA judging system is that anyone can judge. people who don't solve the cube don't have a clue what's going on. This would mean that people who have a non-cuber judge could twist a corner to solve OLL and the judge wouldn't know.
> ...



It's a tricky case, because there may be no way of telling whether the competitor is telling the truth about what happened.

Regulation 11d says it's up to the Delegate to decide, since it's not fully clear what to do in a situation like this.



WCA Regulations said:


> 11d) If the WCA Regulations are not fully clear or if the incident is not covered by the WCA Regulations, then the WCA Delegate must make his decision based on fair sportsmanship.


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## Methuselah96 (Jan 29, 2014)

Methuselah96 said:


> Sorry to bring up an old topic, but what if the competitor knows that he twisted a corner in the middle of the last F2L pair and he knows which corner he twisted. It happens that it would have been an OLL skip. If he twists it back, he is definitely not getting any advantage in solving the puzzle. It would only be an advantage if he didn't know what corner he twisted.



What about this part? This is allowed in competition right? Because, the competitor did not get an advantage because he knew what corner he twisted.


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## Dene (Jan 30, 2014)

It's all very ambiguous, and up to the discretion of the delegate. I can't imagine a situation where I would even bother to punish a competitor if they got a twisted corner. As I said earlier: a twisted corner is punishment enough in the first place.


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## Ross The Boss (Jan 30, 2014)

this just happened to me and im unsure about what the result would be if it were to happen at a competition. i was doing a CFOP solve and i felt a corner twist during f2l. i twisted it back to, what i thought, was the original position. when i got to OLL, it turned out that i actually hadn't twisted it back correctly. should the judge DNF me because it would look like i twisted a corner during f2l with the intention of giving myself an option of what OLL case i want? [just as an interesting sidenote, OLL was one twisted corner =P ]

there is also something else that i thought of while reading through this. it has been established that if OLL is only one twisted corner, the solver should twist another corner than do OLL. but what if this were to happen to a roux user? seeing as roux users orient and permute corners at the same time, having all corners oriented (assuming they are unpermuted) is no more advantageous than any other CMLL case because "the case which you deem to be 'better' or 'worse' is a subjective matter". would the roux user be aloud to orient the single corner or would he have to unorient another corner? 
a simmaler problem arises for people who use some sort of LS method that orients the last layer. if a person using this method ends up with LL unoriented by 1 corner, he should be aloud to twist that corner into position seeing as he has already done the algorithm and is therefor not at any unfair advantage. forcing this person to twist a diferent corner and do another ALG would be putting him at a disadvantage. but then how would a judge know that the solver had actually done an LS alg? this wouldnt really be an issue for an experienced judge, but then again, a judges inexperience could be taken advantage of by a dishonest competitor.


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## TMOY (Jan 31, 2014)

Ross The Boss said:


> this just happened to me and im unsure about what the result would be if it were to happen at a competition. i was doing a CFOP solve and i felt a corner twist during f2l. i twisted it back to, what i thought, was the original position. when i got to OLL, it turned out that i actually hadn't twisted it back correctly. should the judge DNF me because it would look like i twisted a corner during f2l with the intention of giving myself an option of what OLL case i want? [just as an interesting sidenote, OLL was one twisted corner =P ]


Well, no. It' s the same situation as when some pieces pop, you reassemble them and notice at a later stage of the solve that your cube is unsolvable.

5b3b) If, after repairing the puzzle but before the end of the attempt, the competitor finds that the puzzle is unsolvable, he may disassemble and reassemble a maximum of 4 pieces to make the puzzle solvable.
5b3c) If the puzzle is unsolvable, and can be made solvable by rotating a single corner piece, the competitor may correct the corner piece by twisting it in place without disassembling the puzzle.

And yes, you can cheat by using the initial wrong twist to your advantage, but you can as well not do that twist at all, it leads to the same possible cases (up to mirroring) for the unsolvable OLL and you don't waste time twisting a corner for nothing.


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