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Topic: Neighbourhood Pool Watch - page 17. (Read 49925 times)

donator
Activity: 2058
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March 01, 2012, 02:21:50 AM
#40
gah.
didn't think of that.

which pretty much means, there's no way to test it, with only based on data gathered from bitclockers.


That's right. You can just make assumptions and do backtesting.

I'd like to make this plain: now that I have a bit more of an idea about what the 'scammer' tag means, the second case can't make any claims about scamming. It just makes clear that it is much more possible for Bitclockers.com to steal blocks, and that results so far do nothing to disprove the possibility.

The first case (that they have agreed to pay miners a certain amount and did not pay that amount) is really the only situation where lying to wrongfully obtain funds can be proven.
legendary
Activity: 1764
Merit: 1006
March 01, 2012, 02:13:52 AM
#39
gah.
didn't think of that.

which pretty much means, there's no way to test it, with only based on data gathered from bitclockers.
donator
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Merit: 1007
Poor impulse control.
March 01, 2012, 02:05:53 AM
#38
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?
You'd like to assume the population mean to be 1xD and estimate the probability of the round lengths averaging to 1.0281? Using a similar technique to that described earlier (using code similar to this) we get a probability of 0.8801 rounds being less than 1.0281, giving a probability of rounds being 1.0281 or longer at 1-0.8801=0.1199. This is even worse than the estimate I provided earlier.
My statistics are a little rusty, but isn't that result not statistically significant?
i don't think we're testing a hypothesis here. it's just a probability.
yes, it's just based on the cdf.
Quote

...unless organofcorti wants to do a series of real-time test with a similar sized prop pool.

Can't do that either. If we assume the population mean is 1.0*D, we have to assume the distribution is similar to the Bitclockers.com distribution. Can't compare a geometrically distributed round with a bitclockers.com round - they aren't similar.
donator
Activity: 2058
Merit: 1007
Poor impulse control.
March 01, 2012, 02:02:53 AM
#37
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?
You'd like to assume the population mean to be 1xD and estimate the probability of the round lengths averaging to 1.0281? Using a similar technique to that described earlier (using code similar to this) we get a probability of 0.8801 rounds being less than 1.0281, giving a probability of rounds being 1.0281 or longer at 1-0.8801=0.1199. This is even worse than the estimate I provided earlier.
My statistics are a little rusty, but isn't that result not statistically significant?

It's not a p-value, but even so all it means is that you would expect round lengths means of this size to occur once in every nine sets of 325 rounds. You have to decide whether or not that's significant. As a final remark on this I wrote:

In conclusion, I can only prove malicious lying to gain coins in the first case.

But the second case is also important, and on the balance of probabilities could easily be true. Any time a pool does not disclose round statistics, it is too easy to 'fudge' the books and keep the a short round for themselves.
(the second case being what we just discussed)
So I wasn't claiming to prove Bitclockers.com were steaing blocks, just that it was more possible than for pools that post accurate records of round lengths. ( various edits because of my stupidity and feeling under the weather)
legendary
Activity: 1764
Merit: 1006
March 01, 2012, 01:58:27 AM
#36
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?
You'd like to assume the population mean to be 1xD and estimate the probability of the round lengths averaging to 1.0281? Using a similar technique to that described earlier (using code similar to this) we get a probability of 0.8801 rounds being less than 1.0281, giving a probability of rounds being 1.0281 or longer at 1-0.8801=0.1199. This is even worse than the estimate I provided earlier.
My statistics are a little rusty, but isn't that result not statistically significant?
i don't think we're testing a hypothesis here. it's just a probability.

...unless organofcorti wants to do a series of real-time test with a similar sized prop pool.
legendary
Activity: 1204
Merit: 1015
March 01, 2012, 01:55:03 AM
#35
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?
You'd like to assume the population mean to be 1xD and estimate the probability of the round lengths averaging to 1.0281? Using a similar technique to that described earlier (using code similar to this) we get a probability of 0.8801 rounds being less than 1.0281, giving a probability of rounds being 1.0281 or longer at 1-0.8801=0.1199. This is even worse than the estimate I provided earlier.
My statistics are a little rusty, but isn't that result not statistically significant?
donator
Activity: 2058
Merit: 1007
Poor impulse control.
March 01, 2012, 01:20:07 AM
#34
All the evidence proves that HOPPERS are earning less than they expect?

Are the "regular" miners earning less?? If so why would they stay there?

I'm not saying that It's OK to play around with the statistics even if the cause
is OK( In their eyes). Rules are rules.  But I guess the non-hopping miners
don't care as long as they get the share of the pie they expect (as if there
were no hoppers)

What it comes down to is that they agreed to pay miners a certain amount and didn't.

donator
Activity: 2058
Merit: 1007
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March 01, 2012, 01:17:53 AM
#33
What I would like to see is a BOLD PRINT sticky thread at the top of the pools subsection with a rating system based on several criteria. The ratings can include the ability to hop that pool, possible misdeeds of the pool operator that can lower the rating and the names of pools and operators that have actually scammed (like A1).

This is a seriously good idea CBH. I think it would be extra hard works for the mods though. A council made up of respected bitcointalk forum members and poolops might be better doing the ground work, with  DiabloD3, gmaxwell, and MiningBuddy having the last say before anything is posted. I can see lots of disagreements arising. You'd need to have a cumulative rating the way they do in olympic gymnastics from various judges, i think.
donator
Activity: 2058
Merit: 1007
Poor impulse control.
March 01, 2012, 01:10:16 AM
#32
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?
You'd like to assume the population mean to be 1xD and estimate the probability of the round lengths averaging to 1.0281? Using a similar technique to that described earlier (using code similar to this) we get a probability of 0.8801 rounds being less than 1.0281, giving a probability of rounds being 1.0281 or longer at 1-0.8801=0.1199. This is even worse than the estimate I provided earlier.
Quote
Also, I'd like to see some graphs that compare them to the other types of payout methods.
I'm happy to do that. What sort of graphs did you mean?
Quote
The fact the they lied about being proportional means nothing to me. Any issue regarding that should be handled by a local board mod, such as DiabloD3.
It should, since they agreed to pay a certain amount to miners, and then did not pay them that amount.
Quote
I'm just doing a scammer investigation, and so far, all I'm seeing is you bending statistics to give the results you're looking for - a common issue in the field of statistics.
If you'd like to provide examples I hope I'll be able to explain why I wasn't bending statistics and regain your trust.
legendary
Activity: 1449
Merit: 1001
March 01, 2012, 12:41:52 AM
#31
All the evidence proves that HOPPERS are earning less than they expect?

Are the "regular" miners earning less?? If so why would they stay there?

I'm not saying that It's OK to play around with the statistics even if the cause
is OK( In their eyes). Rules are rules.  But I guess the non-hopping miners
don't care as long as they get the share of the pie they expect (as if there
were no hoppers)
legendary
Activity: 1204
Merit: 1015
February 29, 2012, 12:42:17 PM
#30
organofcorti, your problem is that you're assuming that the actual expected round length is supposed to be 1.0281 D. Instead, assume that it's 1.0 D. What is the probability that the measured round lengths would average to 1.0281 D by chance?

Also, I'd like to see some graphs that compare them to the other types of payout methods. The fact the they lied about being proportional means nothing to me. Any issue regarding that should be handled by a local board mod, such as DiabloD3. I'm just doing a scammer investigation, and so far, all I'm seeing is you bending statistics to give the results you're looking for - a common issue in the field of statistics.
legendary
Activity: 1764
Merit: 1006
February 29, 2012, 10:43:56 AM
#29
good job.

well, that means them fuckers have some 'splainin and payment to all of whoever mines there to do.

pitchforks, anyone?
donator
Activity: 2058
Merit: 1007
Poor impulse control.
February 29, 2012, 07:57:44 AM
#28
They are likely lying. However, lying doesn't get people a scammer tag. It is only a problem when they lie to make extra money. However, I'm not seeing any evidence of that. In your link, you only explore case 1. What if, however, the reality was case 2? Also, since their statistics are delayed, what's stopping it from being a hybrid of truth and fiction? If a round is too short, they could pretend that it never happened. If it's too long, they can say it ended early. Done properly, this would equal out over time.

I had thought that accepting they were lying about accurately reporting blocks solved was more inflammatory than accepting they were telling the truth, so I covered what they said was correct. Hoist by their own petard, etc.

If they are lying about reporting block lengths they may be using a simple sort of averaging algorithm as you suggest, but as I discuss here simple averaging algorithms don't match the histograms of Bitclockers.com round length data.

A much more complex algorithm that matches the Bitclockers.com round lengths frequency distributions are possible, but a much simpler and equivalent approach is to use a function on all rounds, not just shorter and longer ones.

I identified several transforms that match the empirical cdf and histograms of the bitclockers.com round length data and discussed them briefly in Neighbourhood Pool Watch1.

So, assuming they are lying to their miners about when (and possibly if) blocks are solved, we have at least two options to investigate:

1. Bitclockers.com are lying to their miners about when blocks are solved but not if blocks are solved.
In this case, they are faithfully recording all shares submitted and changing block lengths to suit themselves. In this case it is simple to show empirically that strategic miners are being underpaid. If this seems to you to be ok, keep in mind that they claim to be a proportional pool. Strategic miners at a proportional pool can expect a certain return on their shares. If they don't receive the expected amount over time, then the pool is not paying out proportionally.

Their "About us" page doesn't mention anything about "hopping protection", just that the pool is a proportional pool. From their website:
If you think its OK to hop pools, than its OK for the pool to hop hoppers.

How can we show that they are underpaying strategic miners without relying on a particular transform or the Bitclockers.com pool op's say so? Well, can use their own data to show the difference between expected share values on Bitclockers.com and a real proportional pool. But since I already did that how about looking at the difference between the expected payout per round for Bitclockers.com compared to a real proportional pool?

The graphs below show how the expected share values and expected earnings vary for bitclockers.com and an actual proportional pool. This data is based on the round lengths published for rounds 180 to 505. The top graph I've published before. The lower graph shows the expected amount a miner can earn by leaving a pool at a particular number of shares. As can be clearly seen, if a strategic miner leaves Bitclockers.com at 0.43xD (the point at which the expected share value drops to zero on a proportional pool) the strategic miner will earn about 0.6 less than expected. So for every 111 btc a strategic miner earns, he or she should have earned 170 btc (not including real world inefficiencies).





2. Bitclockers.com are lying to their miners about if and when blocks are solved.
Part 1. partly covers this. In addition not paying strategic miners their expected reward, Bitclockers.com may be withholding btc from all miners, for example from the very short rounds that they don't report. The possibility can be assessed fairly simply by comparing the distribution of means for bitclockers with other generated random data from distributions that have a similar density plot and cdf to the Bitclockers.com round lengths. See Neighbourhood Pool Watch1 part 1 for details.

Firstly, what does this bitclockers.com data say? The Bitclockers.com mean round length for rounds 180 to 505 is 1.0281. It took 325*1.0281=334.1 rounds of shares to generate 325 bitcoin rewards. That means that they could have taken 455 btc and we'd be none the wiser.

How likely is this to have happened?

Using the three most likely distributions and this R code I generated a million sets of a million generated random numbers for each of the three distributions. I then generated a million means from each set, and found their means of the means and the proportion of them below or equal to D.

From these sets I obtained the following:
Code:
mean(r.mat$rlnorm)
[1] 1.020986
> mean(r.mat$rllogis)
[1] 1.027112
> mean(r.mat$rgamma)
[1] 1.021985
Code:
length(subset(r.mat$rlnorm,r.mat$rlnorm<=1))/length(r.mat$rlnorm)
#[1] 0.1914
length(subset(r.mat$rllogis,r.mat$rllogis<=1))/length(r.mat$rllogis)
#[1] 0.1530
length(subset(r.mat$rgamma,r.mat$rgamma<=1))/length(r.mat$rgamma)
#[1] 0.1682

The means are very close to that for bitclockers.com, and the second group of results show that for round length distributions similar to Bitclockers.com's own, only 0.19 are at D (the bitcoin Difficulty). This means that the for these sets, the mean is much less likely to be D than it is to be larger than D. The very method of generating their fake data - whatever it is - allows a mean to be greater than D 71% of the time. This could easily include hiding btc. Rounds 180 to 505 are Sept 22nd to Feb 17th. So that's an extra bonus to the pool ops of about 90 btc/month in addition to the 2% tax. A nice little earner.

In conclusion, I can only prove malicious lying to gain coins in the first case.

But the second case is also important, and on the balance of probabilities could easily be true. Any time a pool does not disclose round statistics, it is too easy to 'fudge' the books and keep the a short round for themselves.

I hope this clears up any doubt for you.
legendary
Activity: 1204
Merit: 1015
February 28, 2012, 08:35:43 PM
#27
Probably my fault for not making it easier to follow - sorry.

1. We have overwhelming evidence that they haven't been reporting the shares in a round accurately. Without any explanation from them, this is bad. They could be hiding anything with this, including hiding short rounds.
I agree. It is quite clear that the reporting isn't accurate.

2. They have stated that they are accurately reporting rounds as they occur. I provide an explanation here as to why this means (if they're being truthful about block reporting) they've probably been underpaying their fulltime miners by 21%.
They are likely lying. However, lying doesn't get people a scammer tag. It is only a problem when they lie to make extra money. However, I'm not seeing any evidence of that. In your link, you only explore case 1. What if, however, the reality was case 2? Also, since their statistics are delayed, what's stopping it from being a hybrid of truth and fiction? If a round is too short, they could pretend that it never happened. If it's too long, they can say it ended early. Done properly, this would equal out over time.
legendary
Activity: 1764
Merit: 1006
February 28, 2012, 12:02:29 PM
#26
unhoppable. Tongue
legendary
Activity: 1148
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If you want to walk on water, get out of the boat
February 28, 2012, 08:08:01 AM
#25
Just move to p2p, problem solved  Tongue
donator
Activity: 2058
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Poor impulse control.
February 28, 2012, 05:42:56 AM
#24
+1
sent 2btc
Thanks for the support, Graeme. BTC helps me justify my 'hobby' to my SOP when I miss dinner with her parents Wink
Quote
I had also suggesting something like to some others a while back "this I agree that there needs to be some sort of pool oversight, but not in the ad-hoc way I've done it. It needs to be some sort of a council made up of pool ops and miners. I discussed this a bit with MobiusL (his idea) and I like it." It is a good idea and I would be fully supportive - just *how* to audit pools might cause discussion Wink
Published round lengths can be a good start. I have no idea how you'd then audit payments.

Quote
I started a thread so poolops could state what they do with miners shares, it was pretty fail as most didnt post then it was taken offtopic by people that didnt understand what it was for.... I thought it could be a handy quick reference :/


I was kind of hoping your thread would get more substance to it, but maybe some pool ops aren't just using hashes the way we think they are and aren't ready to talk about it yet - apart from Goat that is.
vip
Activity: 980
Merit: 1001
February 28, 2012, 03:43:04 AM
#23


Organofcorti I just sent you 1 BTC to support your efforts for Neighbourhood Pool Watch. I’m fucking sick of all of the careless disregard for any type of oversight to the pool system. I’m glad someone is finally doing something about the problem.

The worst thing we can do is invite people here with our great utopian promises of a better way and then steal from them using what should be the proof of work security system of the currency. It’s pathetic!

+1
sent 2btc


I had also suggesting something like to some others a while back "this I agree that there needs to be some sort of pool oversight, but not in the ad-hoc way I've done it. It needs to be some sort of a council made up of pool ops and miners. I discussed this a bit with MobiusL (his idea) and I like it." It is a good idea and I would be fully supportive - just *how* to audit pools might cause discussion Wink

I started a thread so poolops could state what they do with miners shares, it was pretty fail as most didnt post then it was taken offtopic by people that didnt understand what it was for.... I thought it could be a handy quick reference :/

Keep up the good work organofcorti Smiley

Cheers
Graeme


donator
Activity: 2058
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Poor impulse control.
February 28, 2012, 03:37:30 AM
#22
I do have a horse and can give personal data.

Do you have timestamped shares and payments? Also did you happen to keep your own log of shares submitted (I'm guessing not but thought I'd ask).

PM sent with info, 5BTC also sent thanks for your awesome work, more info will be sent to you as soon as I get it. Thanks.


Thanks for the support Chaang - a few more btc and I'll make it to Tongsai Bay Wink

More data? You know me so well.
donator
Activity: 2058
Merit: 1007
Poor impulse control.
February 28, 2012, 03:01:34 AM
#21
Sorry, guys, but I'm just not seeing it.

Probably my fault for not making it easier to follow - sorry.

1. We have overwhelming evidence that they haven't been reporting the shares in a round accurately. Without any explanation from them, this is bad. They could be hiding anything with this, including hiding short rounds.

2. They have stated that they are accurately reporting rounds as they occur. I provide an explanation here as to why this means (if they're being truthful about block reporting) they've probably been underpaying their fulltime miners by 21%.

3. Their first round under 0.3xD in over 300 rounds occurred just after I made their obfuscations public. That is unlikely to be a coincidence.

4. I've asked them several times to publish their accurate round lengths which they haven't done. In fact I haven't had any response to any allegation I've made. I have sound mathematical backing behind all of my statements. I'm overstating nothing, if anything I'm being conservative.

I'm aware that I'm probably not covering something that you need to know, but if you can post or pm me your requirements I'll know whether or not I can fulfill them without wasting any more time for either of us.

I don't mine with bitclockers and I don't have a horse in this race.



Organofcorti I just sent you 1 BTC to support your efforts for Neighbourhood Pool Watch. I’m fucking sick of all of the careless disregard for any type of oversight to the pool system. I’m glad someone is finally doing something about the problem.

The worst thing we can do is invite people here with our great utopian promises of a better way and then steal from them using what should be the proof of work security system of the currency. It’s pathetic!



Thanks for the btc CornedBeefHash - I promise I'll give it a good home.

I agree that there needs to be some sort of pool oversight, but not in the ad-hoc way I've done it. It needs to be some sort of a council made up of pool ops and miners. I discussed this a bit with MobiusL (his idea) and I like it.

Also, don't forget we put Maged in a hard position here. In other cases of scamming it's usually clear cut and the evidence doesn't require a knowledge of statistical probability in order to follow it.

Assessing whether or not a pool has been acting in poor faith is much harder. Maged must also realise that this is a test case and probably doesn't want a situation where at any time in the future a miner gets pissed at a pool he can refer back to this and cause unnecessary problems.

I'm happy to go along with the process since I'm sure I'll be able to supply whatever proofs I need to.

Cheers again for the support - always good to hear.
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