Other weekly pool statistics posts
- Added Viabtc.
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 months–long 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
- 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):
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.
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.
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.
- 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!