October 23rd 2016 Mining Pool Statistics



Other weekly pool statistics posts
Weekly network statistics posts
Weekly block maker statistics posts

Changelog:

  • Added Viabtc.
Errorlog:
  • Nil.
To do:

  • Nil.

0. Viabtc.com added to the weekly stats
Viabtc.com, famous (or infamous, depending on your point of view) along with the bitcoin.com mining pool for supporting Bitcoin Unlimited, has been added to the weekly stats. This is an interesting pool — I don’t see blockchain payouts to more than about 80 miners, but a huge pool hashrate. Worth looking at further.

1. GHash.IO closing
The curse of the of the fifty percent club strikes again! With the recent announcement of the closure of GHash.IO all the pools that have controlled more than 40% of the network hashrate for any length of time — DeepBit, BTC Guild and GHash.IO — have all closed (DeepBit lost miners and BTC Guild pool op due to concerns of legality of pooled mining in a post BitLicense world).

The loss of interest in GHash.IO seems to be due to a number of factors:

  • Some miners moved after the pool reached above 40% of the network for a short time.
  • The pool size reduced as their private mining for CEX.IO became unprofitable. Smaller pool size means more variance, and many miners tend to be risk averse even over shorter time periods.
  • The largest impact was due to monthslong stratum exploit that other pools had patched. Unfortunately, even though we’d discussed their unlikely bad luck with them, it was some time before they implemented the solution. As far as I know there was no reparations to affected miners, and many left

I’m sad when any pool ends – it reduces the diversity of pools out there, which makes it harder for small miners to get interested in mining. Still, I can’t help but read the fall of GHash.IO as a cautionary tale about the importance of listening to your customers and keeping them happy.

  







  • FAQ: Bitcoin mining and luck

Explanation of the tables and charts

Pool reported block history statistics. This table lists all statistics that can be derived from the number of blocks a hashrate contributor has solved for the past week using all solved blocks – both valid and orphaned – and difficulty 1 shares per round. 
  • A much more accurate estimate of the hashrate, confidence intervals are unnecessary.
  • Orphan races lost, and percentage of  solved blocks that were not added to the blockchain.
  • “Luck” is the usual difficulty 1 equivalent shares per round / mining difficulty,  or (equivalently) accepted shares / expected shares.
  • CDF: The cumulative density function (CDF) measures the percentage of the time this number accepted shares / expected shares would be less than the calculated value, given the number of valid + invalid blocks.
  • Pool profitability compares variables such as total number of shares in a week and total reward (including transactions) in a week with the expected reward per share as follows (pool fee not included):

a = reward estimate (tx-free bitcoin rewards) per valid block including orphaned blocks 
b = estimated difficulty 1 shares for valid blocks
c = actual rewards for valid blocks
d = submitted difficulty 1 shares for all blocks including orphaned blocks

Actual reward per share = c / d
Theoretical reward per share = a / b

Profitability = Actual reward per share /  Theoretical reward per share








Average hashrate per solved block (valid + invalid)
Hashrates are calculated from the pool reported difficulty-1 equivalent shares per round and the pool reported block solve times for all solved blocks, both valid and invalid. 



Average Pool profitability per week and per block
Pool profitability compares variables such as total number of shares in a week and total reward (including transactions) in a week with the expected reward per share. Pool fee is not included, but this is a good basis on which to compare pools, as long as you’re aware of pool fees, whether transaction fees are paid to you, and whether or not the pool is paying for   orphaned blocks. Details of the profitability calculation are given in the block history table.

Obviously these charts are only relevant to miner income if the reward method is not PPS; however the charts can also be interpreted as the profitability of the pool, so it might give you some insight into the financial health of a PPS pool.

The average profitability per week chart is a kernel smoothed average, with a bandwidth of 500 blocks (same as the orphan plot). Pools are only included if they have solved 500 or more blocks and have made a block during the current week.




Density of orphaned blocks
This chart shows the density of orphaned blocks per pool, as a function of blocks solved by that pool. The fringe indicates the actual occurrences of the orphaned blocks, and the colour of the line and fringe indicate the approximate date.





Pool user hashrate and combined user hashrate densities
The top facet of this chart shows the proportion of user accounts with a given hashrate – the thicker the “violin” the greater the density of user accounts with a particular hashrate.

The bottom facet is the same data, weighted by hashrate. In effect, it shows what proportion of the pool’s hashrate is supplied by particular hashrates. The area of the “violins” is proportional to their total hashrate.

Note that for some pools the hashrate is averaged over twenty four hours, some pools are averaged over an hour or more and some for only fifteen minutes, so expect some variance in the results.



Gini coefficient for miner hashrates

The Gini coefficient measures inequality, as is further discussed here. In the plot below, it is measuring inequality within public mining pools. The lower the coefficient, the less inequality in the pool.


These indices are much higher than most things for which the Gini coefficient is calculated. For example in countries with notoriously unequal incomes it is rarely above 65% (Seychelles, 2007), and educational inequality in the poorest countries comes close, at 92% (Mali, 1990). There are a large number of bitcoin miners with near (or less than) zero income, and a small few who actually make a living.


“All combined” is the Gini coefficient for miners at all pools that can be monitored, combined. It is more affected by larger pools and less affected by smaller pools. 





Organofcorti lives in the blockchain!

organofcorti.blogspot.com is a reader supported blog:

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Created using R and various packages, especially dplyr, data.table, ggplot2 and forecast.

Thank you to blocktrail.com for use of their address data, and coincadence.com for their p2pool miner data.


Thanks also to Matt’s Alternative AntPool API for AntPool block data.

Find a typo or spelling error? Email me with the details at organofcorti@organofcorti.org and if you’re the first to email me I’ll pay you 0.01 btc per ten errors.

Please refer to the most recent blog post for current rates or rule changes.

I’m terrible at proofreading, so some of these posts may be worth quite a bit to the keen reader.
Exceptions:
  • Errors in text repeated across multiple posts: I will only pay for the most recent errors rather every single occurrence.
  • Errors in chart texts: Since I can’t fix the chart texts (since I don’t keep the data that generated them) I can’t pay for them. Still, they would be nice to know about!
I write in British English.






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