

Analyzing the 2013 Bitcoin fork: centralized decision-making saved the day - randomwalker
https://freedom-to-tinker.com/blog/randomwalker/analyzing-the-2013-bitcoin-fork-centralized-decision-making-saved-the-day/

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wsr
This might be a silly question, but why was there a fork in the first place?
The article wasn't as clear on explaining that part. Can someone else
elaborate on that part?

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scrupulusalbion
A fork on the blockchain will only ever occur if one or more nodes are
operating on different rules; the danger of a fork is proportional to the
number of nodes that differ on those rules, because it would waste miner
resources.

Suppose Node A thinks that a block should be no larger than 1MB, but Node B
thinks that a block can be as large as 2MB. When a client presents a 1.5MB
block to both nodes, Node A rejects it for being too big but Node B accepts it
for being small enough. Since clients and miners ask for new blocks from
nodes, anyone that asks for blocks from Node A would not get the 1.5MB block,
but would get it if they had asked Node B. If 10% of node agree with Node A,
then the 1.5MB block could be gotten by a lot of clients and miners, but not
all. If 50% agree with Node A, then you have a serious problem in which a lot
of people are not going to get the 1.5MB block and a lot of miners will spend
their time on it for probably no ultimate benefit.

Thus, the problem does not really begin until any miners start accepting
blocks from the chain of blocks that will eventually be rejected by the
network generally. Unfortunately, there is no way to tell ahead of time which
is the right side of the fork, but this could last for hours. So, fork
detection is critical to avoidance of wasting precious mining resources.

