Thank you for following these evolutions and thanks for mentioning me!

***UPDATE*** : To create this report, I used **[SteemSQL.com](https://steemit.com/steemit/@arcange/steemsql-com-a-public-sql-server-database-with-all-steemit-blockchain-data)** database.
Check this [post](https://steemit.com/steemit/@arcange/steemsql-com-a-public-sql-server-database-with-all-steemit-blockchain-data) for more info and this [post](https://steemit.com/steemit/@arcange/steemsql-com-how-to-create-a-steem-analytic-report-with-microsoft-excel) on how to do it.

Good job gathering statistics.  I would like to point out some extra facts for those concerned about the fall in diversity of miners.

## 50+ Runner Up Witnesses 

In addition to the top 19 witnesses, there are over 50 accounts that produce blocks at least once per day if not many times per hour.  Combine this with the top 19 witnesses and the top two miners and you get over 70 unique individuals producing blocks on a daily basis.   

To put this in perspective, there can be at most 144 unique individuals producing blocks on a daily basis with Bitcoin.   In any given hour only 6 unique individuals produce and validate Bitcoin blocks, whereas Steem has at least 30+ unique individuals per hour (maybe much more, I didn't actually count).  

The numbers 144 and 6 are assuming all blocks are produced by *different people*, but in reality only 9 unique individuals (pools) confirm blocks each day.  In any given hour less than 5 people confirm blocks because some pools get lucky and produce twice in the same hour.  Imagine rolling a 9 sided die 6 times, [the probability that a given hour will have the same pool selected twice is 90%](https://lazycackle.com/birthday-problem-calculator.html).

## Purpose of Proof of Work 

The purpose of Proof of Work is to make the blockchain computationally expensive to forge.  Regardless of how many unique individuals are mining, we know that a certain number of calculations must be performed for a given proof of work threshold.  

Someone who implements a GPU algorithm is able to perform these calculations more cheaply than someone with a CPU.  This increases their profit margins.   The market always responds when someone is earning guaranteed oversized profits.  Right now the proof of work is rewarding those who did the *programing work* necessary to increase computations.  

## Transactions as Proof of Stake 

Every user who uses the blockchain is also participating in directly confirming the current blockchain state.  Each transaction includes the block ID of a recent block. A forged chain would be unable to migrate all of the user activity and therefore is easily identifiable by simply looking at the stake-weighted average time since each account last transacted.  

Steem is secure, the market for computational power is functioning, things will evolve just as they did with Bitcoin.  One day there may even be ASIC miners.

well send to the gpu bounty what you will make from these posts (this one and the previous...)
hmm less than 70$ lol never mind

Good info. If/when it becomes public I will point a few miners that way to try it for sure!

Good presentation and good points too .  keep it up