# How do you treat screw-ups in big averages?



## amostay2004 (Sep 13, 2009)

So I wanted to do an average of 100 today and things were going well. I had a few pops and I ruled them as DNF so they don't affect the session mean. All times were sub-16 with the exception of one or two solves (I was aiming for sub-14 average of 100) until I screwed up a solve which ended up as 20secs and I was kinda pissed as it added 0.1-0.2 to the mean (which is a LOT as I was barely sub-14 that time)

So for you guys out there who like to do big averages..how do you account for:
1. POPs
2. solves without pops but screwed up (eg. wrong F2L pair, wrong OLL/PLL, major lock up)

I so want to rule screwed up solves as DNFs but it seems to make me feel guilty 

Any opinions?


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## Carrot (Sep 13, 2009)

amostay2004 said:


> So I wanted to do an average of 100 today and things were going well. I had a few pops and I ruled them as DNF so they don't affect the session mean. All times were sub-16 with the exception of one or two solves (I was aiming for sub-14 average of 100) until I screwed up a solve which ended up as 20secs and I was kinda pissed as it added 0.1-0.2 to the mean (which is a LOT as I was barely sub-14 that time)
> 
> So for you guys out there who like to do big averages..how do you account for:
> 1. POPs
> ...



I just submit the slow time... I don't DNF them... with just 1 DNF you will get a mean called DNF... and that's really ruining a mean of something =)


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## amostay2004 (Sep 13, 2009)

Okay mean was probably the wrong word..what I meant was the 'Session average' figure in CCT which averages out all non-DNF times..so yea


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## qqwref (Sep 13, 2009)

I think that if you want to do an average of 100 you have to do it legit. At max you can have one DNF in the average, anything more and it doesn't count. If you're popping maybe you should use a different cube or something - it may not matter for an average of 12 but if you are doing something longer that starts to be an important thing to pay attention to.


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## amostay2004 (Sep 13, 2009)

But isn't the purpose of a big average to somehow estimate what your true average is? I mean if one pop in an average of 12 is tolerable why can't a few pops in an average of 100 be accepted?

I'd say it's not easy even for a cube that seldom pops to get 1 or 0 pops in 100 solves. And if you'd have to have much slower times to fix pops to not result in a DNF..it will pretty much spoil the average and not represent your true average


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## Muesli (Sep 13, 2009)

On cubetimer I decide at what time limit I will allow. It's often 40 seconds. Any more than that, and I call it a DNF and delete the time.


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## qqwref (Sep 13, 2009)

amostay2004 said:


> But isn't the purpose of a big average to somehow estimate what your true average is? I mean if one pop in an average of 12 is tolerable why can't a few pops in an average of 100 be accepted?
> 
> I'd say it's not easy even for a cube that seldom pops to get 1 or 0 pops in 100 solves. And if you'd have to have much slower times to fix pops to not result in a DNF..it will pretty much spoil the average and not represent your true average



Your "true average" includes the times you mess up! It's the average time I'd expect you to solve it in if I just gave you your scrambled cube and said "solve this", and as a spectator I'm certainly not going to just let you not count that one if the cube explodes. If you don't count the times you messed up, then you're misrepresenting yourself, because the average is then actually the true average of a theoretical version of you who never makes mistakes or pops. 

One pop per average is tolerable because we conventionally trim off the single best and single worst time in each average. One alternative way of doing an average, to take into account multiple pops, is to just trim a larger number of times on both sides. So if you got 5 pops in an avg100, you can trim those off, but you also have to trim off the 5 BEST solves you had. That's the only way to fairly take into account a large number of pops.


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## Raffael (Sep 16, 2009)

amostay2004 said:


> ..
> I'd say it's not easy even for a cube that seldom pops to get 1 or 0 pops in 100 solves.
> ..



False.
I just recently did an average of 100 without a single pop.
I use a 25th anniversary Rubik's storebought. It's something like 3 years old now, so i know pretty good how to handle it.
(e.g.: a ccw u-perm i use: R2 U' R' U' R U R U R U' R
By now i have learned, that i have to be *very* acurate on the last R U' R, else my cube will pop. Hence, I pay attention and am very acurate if i don't want to POP.)

Just make sure, you know when your cube tends to POP and then pay attentention to avoid POPping.


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## Tim Major (Sep 16, 2009)

most timers allow you to delete times. just count the bad times. if you took out a few bad times, you would have to take out the best times as well like in a5 or a12. tighten your cube


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## amostay2004 (Sep 16, 2009)

Raffael said:


> amostay2004 said:
> 
> 
> > ..
> ...



I agree..it is possible..just not easy. And I tend to pop more on R' U R' though. My new main cube is more likely to pop and I'm still trying to adjust to decrease my popping rate.

As for suggestions to delete both bad times and best times..that might be a good idea. Bad times, especially with pops, can go up to 30+ seconds while good times don't get too good to bring down the average. 

What I'm trying to point out is that I wanna cut off outliers in an average that is most unlikely to happen in a 'normal' solve so that it doesn't distort the average.

I hope I made sense


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## mazei (Sep 16, 2009)

Then what about people like me qq.

I log a session of 500 solves and most of the time there is >30 POPs. Can even reach the 60s.


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## Escher (Sep 16, 2009)

When I cubed (but I'm still here, damn), my main cube (type C, c4u core + screws/springs) went for 2-3 weeks sometimes before it popped once. In that time I could've done 5-8000 solves.

EDIT:
on-topic: Depends. My general method was to clear the session every time I had a pop, or DNF, or bad solve. It meant I'd end up doing about 500 solves and have about 12 of them logged, and sometimes they'd be new PBs  Unless I was doing very well when I had one of the above, in which I'd just keep going and try and roll it out, which would usually end up with me recording loads and loads of times.


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## amostay2004 (Sep 16, 2009)

Escher said:


> on-topic: Depends. My general method was to clear the session every time I had a pop, or DNF, or bad solve. It meant I'd end up doing about 500 solves and have about 12 of them logged, and sometimes they'd be new PBs  Unless I was doing very well when I had one of the above, in which I'd just keep going and try and roll it out, which would usually end up with me recording loads and loads of times.



That's what I usually do..but I figured I should stop it and start doing longer averages to improve on consistency. When I start a new session every time I have a bad solve..I sort of do it with the feeling: 'it's okay if this solve suck..i'll start a new session'. I think it's better to go 100% on every solve...

off-topic: you QUIT? why???


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## Escher (Sep 16, 2009)

amostay2004 said:


> off-topic: you QUIT? why???



off-topic: well... despite finishing school I'm doing another A-level and 3 retakes in January that I have to do ridiculously well in, plus I got dumped and I could foresee I'd spend loads of time up in my room cubing and not doing anything worthwhile, and I couldn't really see myself getting that much better, and all my puzzles were pretty crap...
I've no doubt I'll start again soon enough, I just need to sort out important stuff first.

on-topic: Maybe you should do cubing practice with a much tighter cube so that you're forced to turn more accurately. When you go back to your competition cube, you're then less likely to pop and you might even improve your tps.


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## mazei (Sep 16, 2009)

Isn't it the opposite way. Play with a loose cube to improve accuracy and go competitions with a tighter cube but as or not, even more smooth.


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## Escher (Sep 16, 2009)

mazei said:


> Isn't it the opposite way. Play with a loose cube to improve accuracy and go competitions with a tighter cube but as or not, even more smooth.



Either way, you could practice with a very very loose cube so that you have to turn more accurately to not pop, or you could practice with a very very tight cube so that you get used to not being able to cut corners.


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## phases (Sep 16, 2009)

I dunno about POPs as I've never had one. But I feel if you DNF you should record that, and if you have a long - screw up - solve you definitely should include that too. You're getting your average, not your average of your best solves.

..that being said, sometimes I get a 2 or more that are 2x as long as it they shoulda been and I get pissed and quit the session and try again later. Even though I shouldn't. Other times I force myself to complete it and just see how close to my best average I can get by trying to make them up with real good solves.


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## JBCM627 (Sep 16, 2009)

I used to throw out times that were more than 2 standard deviations away from the mean - this usually gets rid of excessively slow or extremely lucky time. I'd consider the average after throwing away times slightly more accurate, since it more closely resembles the most probable time.

I also remember thinking that since the distribution of your times might be better approximated by an inverse Gaussian distribution, the straight-up mean is probably not the best measure of your times - the peak value of this function may be a better measure (it will give you the most probable value). While this may or may not work, either way I came across a better method to approximate times as a smooth probability distribution function. If anyone is interested, I wrote a Mathematica notebook that will approximate your solves (or... anything) as a smooth probability density function, and give you the most probable value. You'll have to PM me to get the notebook if you want it, since I can't attach it.

Using a sample distribution of ~800 times, you can see what I mean (attached). This distribution is somewhat bimodial, since the 800 times are from a couple years worth of times - I've improved . Still, I sort of consider the most probable value a better representation of where I'm at than the mean.


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## amostay2004 (Sep 16, 2009)

Duuuude....that seems like too much effort to determine my average..haha. And I have the mathematical understanding of a 15-year old..

I think I'll just stick to recording pops as DNF..but I'll limit it to at most 5 per average of 100..I've switched my main cube back to the previous one which pops lesser 

As for terribly screwed up solves..I'd be too guilty DNF-ing them anyway so I'll count them in the average or just start a new one


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## shelley (Sep 17, 2009)

Come on, seriously? Do you also throw out the fast times you got because you got lucky? $20 says you don't. Besides, the session average stat in CCT doesn't mean much anyway. You could DNF 99 solves and get one 10 second solve and it'll report your session average as 10 seconds. Is that a good estimate of what your "true" average is?

And if your cube is popping that often, try adjusting the tension or your turning technique.


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## amostay2004 (Sep 17, 2009)

There's probably no accurate way of determining my "true" average so these seem reasonable to me..

1. No I don't throw out fast, lucky times
2. I won't throw out bad, screwed up, unlucky (if unlucky solves exist), yet non-popping, times either
3. I'd limit DNFs to 5 out of 100 as stated earlier which is a pretty reasonably rate IMO since in an official competition you only do 5 solves in an average. If I pop 5 or less times in 100 solves it's pretty reasonable to call them 'abnormal' times that would distort the average. Of course, less than 5 is always better

I've changed my cube to a less-popping one so I'm pretty sure it's achievable 

Or does anyone else have a better suggestion to determine one's "true" average, if there is actually such a thing?


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## qqwref (Sep 17, 2009)

What about this: just trim off the best 25% and worst 25% of solves. Sure, you'll end up discarding every decent time you have, but no especially good/bad times will affect your mean (unless you are unbelievably inconsistent).


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## blah (Sep 17, 2009)

Maybe I should add a function in my timer to trim off as many of the best times as the number of DNFs and calculate a DNF-less session average. Or maybe you could do that to qqTimer, Michael, I don't have the time to do anything right now, there are so many bugs at the moment it's unbelievable 

It's a thought, no?


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## amostay2004 (Sep 18, 2009)

@qqwref: Well it is possible and sounds reasonable..only thing is it takes some effort to manually cancel out the times, which comes to...

@blah: That'd be cool..but first please fix your SD calculation


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## mazei (Sep 18, 2009)

How about a more of modal class of times function since that kind of seems more fitting in the situation qqwref is asking for?(Well in my very shallow pool of knowledge, it seems the most fitting. Any better, please suggest)


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## miniGOINGS (Sep 18, 2009)

Just calculate the median of your times. That's what I would do, sounds pretty accurate to me.


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## hawkmp4 (Sep 21, 2009)

I like the idea of leaving everything and trimming off as many good times as DNFs. Seems to be the fairest way to go if you don't want bad solves in there. Then again...
I think that a POP raises your average much more than one lucky solve lowers it. For example, if I'm averaging 30s right now (which I am) and I pop and try to finish the solve, lets say I get a minute twenty. That's gonna raise my average much more than even an LL skip could.


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## mazei (Sep 21, 2009)

When we POP, we DNF.


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## Mike Hughey (Sep 21, 2009)

mazei said:


> When we POP, we DNF.



What does that mean?


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## amostay2004 (Sep 21, 2009)

@ hawkmp4: Yeap. True 

@ mazei: Well in official competitions you do get the choice to DNF the solve or fix it back and continue


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## rjohnson_8ball (Sep 21, 2009)

I propose a big session be in multiples of 12 solves, with 1/12 of the best removed, 1/12 of the worst removed, and the rest averaged. For example, 120 solves with 10 best removed, 10 worst removed, and the remaining 100 averaged. An alternative method would be to just do ten separate sets of 12, removing 1 best and 1 worst from each, averaging the remaining 10 in each, then averaging the ten averages.


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## Anthony (Sep 21, 2009)

rjohnson_8ball said:


> I propose a big session be in multiples of 12 solves, with 1/12 of the best removed, 1/12 of the worst removed, and the rest averaged. For example, 120 solves with 10 best removed, 10 worst removed, and the remaining 100 averaged. An alternative method would be to just do ten separate sets of 12, removing 1 best and 1 worst from each, averaging the remaining 10 in each, then averaging the ten averages.



I really like that idea. In an average of 100 it's really easy to get a few bad pops that can mess you up. But I guess some would argue that doing it the current way better represents your "real" average.


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## Meisen (Sep 21, 2009)

In my humble opinion the best would be to count all times, even the ones where you screw up.

If you pop once, solve the cube 102 times, remove the pop and the fastest time.
If you pop twice, solve the cube 104 times, remove the two pops and the two fastest times, and so on and so on.

The same principle applies to DNF's ofcourse.

This will give you a true average of 100.


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## Mike Hughey (Sep 22, 2009)

I prefer the "real man's" approach. A DNF means your average is a DNF and you get to start over. 

(But I'm guessing almost everyone could have guessed that about me.)

Almost all of my averages of 100 have included at least one time over 40 seconds.


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## amostay2004 (Sep 22, 2009)

rjohnson_8ball said:


> I propose a big session be in multiples of 12 solves, with 1/12 of the best removed, 1/12 of the worst removed, and the rest averaged. For example, 120 solves with 10 best removed, 10 worst removed, and the remaining 100 averaged. An alternative method would be to just do ten separate sets of 12, removing 1 best and 1 worst from each, averaging the remaining 10 in each, then averaging the ten averages.



That agrees with what some people here are thinking (including me)..only thing is that it's quite a hassle to go through 100 times and cancel out the best and worst times..(or does CCT have a function to customize that?) If popular timers like CCT would add in a 'true average' feature where it calculates in a similar way (best and worst n number of solves removed)..a lot of people would start using that figure as their average I think



Mike Hughey said:


> I prefer the "real man's" approach. A DNF means your average is a DNF and you get to start over.
> 
> (But I'm guessing almost everyone could have guessed that about me.)
> 
> Almost all of my averages of 100 have included at least one time over 40 seconds.



It can be quite demotivating though. Especially when you're doing really great and all of a sudden a huge pop happens and 8 pieces fly around the room


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## shelley (Sep 22, 2009)

amostay2004 said:


> 1. No I don't throw out fast, lucky times
> ...
> 3. I'd limit DNFs to 5 out of 100 as stated earlier which is a pretty reasonably rate IMO since in an official competition you only do 5 solves in an average. If I pop 5 or less times in 100 solves it's pretty reasonable to call them 'abnormal' times that would distort the average. Of course, less than 5 is always better



If you allow yourself to discard 5 DNFs out of 100 you also need to discard your 5 fastest times when calculating your average.


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## amostay2004 (Sep 22, 2009)

Well..fast, lucky times do not always mean the _best_ times. They can be fast but I might have more than 5 non-lucky faster times in an average.

And yes I do agree with discarding the 5 fastest times but they don't necessarily have to be lucky..sorry if I was unclear about that (but then again the 'throw out both fastest and slowest times' hasn't come into discussion yet when I made that post )


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## hawkmp4 (Sep 22, 2009)

Mike Hughey said:


> I prefer the "real man's" approach. A DNF means your average is a DNF and you get to start over.
> 
> (But I'm guessing almost everyone could have guessed that about me.)
> 
> Almost all of my averages of 100 have included at least one time over 40 seconds.



+1
POPs are not just bad luck, they're a result of a combination of poor cube set up and sloppy turning. I think that's important to note in any reflection of a cuber's skill.


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## Tomarse (Sep 27, 2009)

You treat a screw up by throwing your puzzle in a downward motion towards the nearest hardest bit of concrete you can find and then sit down for 30 minutes sulking like a 4 year old  Oh wait, thats just me?


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