<p>A fork choice rule is a general term.</p>

<p>For some history I've found, one of the early written descriptions of the term is from March 2017
<a href="https://medium.com/@VitalikButerin/minimal-slashing-conditions-20f0b500fc6c" rel="nofollow noreferrer">https://medium.com/@VitalikButerin/minimal-slashing-conditions-20f0b500fc6c</a></p>

<blockquote>
  <p>A fork choice rule is a function, evaluated by the client, that takes
  as input the set of blocks and other messages that have been produced,
  and outputs to the client what the “canonical chain” is.</p>
</blockquote>

<p>August 2015 may be the first time "fork-choice rule" was written in a blog post.
<a href="https://blog.ethereum.org/2015/08/01/introducing-casper-friendly-ghost" rel="nofollow noreferrer">https://blog.ethereum.org/2015/08/01/introducing-casper-friendly-ghost</a></p>

<p>The 2013 <a href="https://eprint.iacr.org/2013/881.pdf" rel="nofollow noreferrer">GHOST</a> paper is one of the earliest, prominent publications of a fork choice rule different from Bitcoin's, but it did not specifically mention the term. </p>

CC BY-SA 4.0
2019-07-05T00:35:37.413Z
2019-07-05T00:35:37.413Z
eth
<p>Is "Fork choice rule" a general term including all the algorithms used for choosing a branch among other branches in a fork (including longest chain rule in Bitcoin etc) ? 
Or is it a specific algorithm designed for Casper Ethereum ? </p>

<blockchain-fork><ethereum><terminology><best-chain>
"Fork choice rule" : A general term? or a specific algorithm?
Questioner
# "Fork choice rule" : A general term? or a specific algorithm?

(Asked by: username_0 on 2019-07-02)

Is "Fork choice rule" a general term including all the algorithms used for choosing a branch among other branches in a fork (including longest chain rule in Bitcoin etc) ?
Or is it a specific algorithm designed for Casper Ethereum ?

**Tags:** blockchain-fork, ethereum, terminology, best-chain


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## 1 answers

### Answer by username_1 on 2019-07-05. Score: 1 | Accepted answer

A fork choice rule is a general term.

For some history I've found, one of the early written descriptions of the term is from March 2017
<https://medium.com/@VitalikButerin/minimal-slashing-conditions-20f0b500fc6c>

> A fork choice rule is a function, evaluated by the client, that takes
> as input the set of blocks and other messages that have been produced,
> and outputs to the client what the “canonical chain” is.

August 2015 may be the first time "fork-choice rule" was written in a blog post.
<https://blog.ethereum.org/2015/08/01/introducing-casper-friendly-ghost>

The 2013 [GHOST](https://eprint.iacr.org/2013/881.pdf) paper is one of the earliest, prominent publications of a fork choice rule different from Bitcoin's, but it did not specifically mention the term.


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