What is a dynamic block?

 It is March 2016 and there are many months in which it has been talking about a key issue among the community: the size of the blocks of the Bitcoin network should have due to the growth in the pace of transactions that is developing on it.

Core? Classic? Unlimited?
Surely you have heard of many clients (purses) that present some options or others and the truth is that they have led to intense debates in the main communication channels of bitcoin users, even reaching direct accusations between all parties. It is clear that we are dealing with a delicate issue and each one tends to defend that their proposal is the best.

From Bit2Me we are not going to enter which option is better than another or which project is more optimal for the future. The idea is that after reading this article you have learned something new related to Bitcoin and what better than to explain the proposals that have come up to date about a possible dynamic block size. None of the aforementioned proposals has presented it as a starting point could be an interesting option that is beginning to be discussed after the "Bitcoin Improvement Proposal”Under the title of“Adaptive blocksize”Which has been published by kleetusby Bitpay.

HIGHLIGHT: this is not a new idea and there have been several members of the community like Meni Rosenfeld o upalc who have already dealt with the subject before.

In this post we will focus on the BIP (Bitcoin Improvement Proposal). of Upal and Bitpay trying to explain in a clearer way and in Spanish both proposals so that you do not lose detail and the idea that they intend to transmit for dynamic blocks that help avoid a stagnation in the scalability of Bitcoin is clear to you.

Maximum dynamic block sizes - Upal

Dynamically Controlled Bitcoin Block Size Max Cap

In this proposal, Upal proposes to replace the maximum fixed size with a dynamically controlled maximum block size and that it can increase or decrease with the change in difficulty depending on various factors of the network. These are his two proposals:

• Dynamic Blocks depending solely on the calculation from the size of the previous block.
• Dynamic Blocks depending on the calculation of the size of the previous block and the fees of the transactions received by the miners.

With the increase in adoption, the volume of transactions on the Bitcoin network is destined to grow progressively. For upal, not swapping the 1 megabyte limit for a flexible one would hamper Bitcoin adoption and growth.

First proposal: depending only on the previous block

SI more than 50% of the block sizes found in the first 2000 of the last period of difficulty are greater than 90% of their capacity
SO MaxBlockSize is folded

YES NO YES more than 90% of the block sizes found in the first 2000 of the last difficulty period is less than 50% of the maximum capacity of a block
SO the MaxBlockSize will be half

SINO
SO the same MaxBlockSize will remain

Therefore, this option would not only increase the size of the blocks, but could also be reduced depending on the needs of the moment.

Second proposal: depending on the calculation from the previous block and the transaction fees received by the miners

TotalBlockSizeInLastButOneDifficulty = Sum of all block sizes from the first 2008 blocks in the last 2 difficulty periods
TotalBlockSizeInLastDifficulty = Sum of all block sizes of the second 2008 blocks in the last 2 difficulty periods (This includes 8 blocks of the penultimate difficulty)

TotalTxFeeInLastButOneDifficulty = Sum of all transaction fees for the first 2008 blocks in the last 2 difficulty periods
TotalTxFeeInLastDifficulty = Sum of all transaction fees of the second 2008 blocks in the last 2 difficulty periods (This also includes 8 blocks of the penultimate difficulty)

SI (((Sum of the size of the first 4016 blocks in the last 2 difficulty periods) / 4016> 50% MaxBlockSize) Y (TotalTxFeeInLastDifficulty> TotalTxFeeInLastButOneDifficulty) Y (TotalBlockSizeInLastDifficulty> TotalBlockSizeInLastButOneDifficulty))
SO MaxBlockSize = TotalBlockSizeInLastDifficulty * MaxBlockSize / TotalBlockSizeInLastButOneDifficulty

YES NO YES (((Sum of the size of the first 4016 blocks in the last 2 difficulty periods) / 4016 <50% MaxBlockSize) Y (TotalTxFeeInLastDifficulty <TotalTxFeeInLastButOneDifficulty) Y (TotalBlockSizeInLastDifficulty <TotalBlockSizeInLastButOneDifficulty))
SO MaxBlockSize = TotalBlockSizeInLastDifficulty * MaxBlockSize / TotalBlockSizeInLastButOneDifficulty

SINO The same MaxBlockSize remains

This option contemplates a stable reward for the miners by not increasing the maximum size of the blocks until the transaction fees are not increasing and creating a strong pressure on the cost per transaction. In addition, and despite being dynamic blocks, it is difficult to try to "trick" it because the increase or decrease would occur in the same proportion as the average increase or decrease in the block size.

Maximum block size based on average block size - Bitpay

Maximum Block Size Consensus Rule Based On Median Block Size

BIP published on March 22 by Kleetus from Bitpay proposing a dynamic limit based on the average block size of the last 12960 blocks (approx 3 months of transactions) multiplied by 2 and calculated when a block is already connected to the blockchain, increasing or decreasing following the actual use of the network.

Formula proposed in the BIP to calculate the size of the blocks every 3 months approximately:

median = ((blocksizes [6480] + blocksizes [6479]) / 2)
median * 2 (2 is the growth multiplier)

If the median is less than 0.5MB, the maximum block size will be 1MB until the next calculation. But 2 for the median will be the final increase in the maximum size per block.

According to Bitpay, all of these metrics worked well to react as quickly as possible to market forces without being excessively volatile. Except for the limbs, other options for a period hindsight would work just as well. With his proposal, the miners would have more options when delimiting the size of the blocks created. Some will want larger blocks to minimize transaction confirmation times, and others will prefer to remain conservative.

We are talking about two proposals that undoubtedly enrich the Bitcoin ecosystem. With this introduction to both, you can no longer say that you are not up to date! ? From here, it is time to view and analyze all the tests that are carried out as a test to verify the viability of all the proposals around the dynamic blocks.