Add explanation describing chain splits

[wbnns]

Since the alert went live last night, I've read a lot of feedback from people who are confused about what a chain split is and are asking others to ELI5 (explain like I'm 5).

This PR adds a brief, high level overview of what a chain split is to the beginning of the post. Unless there is any strong objection that anything I've said is fundamentally incorrect in describing a chain split, I will merge this today at 18:00 UTC. Also, if anyone would like to suggest any improvements or additional copy, please feel free to submit a PR to my branch before then (wbinns-split-updates-0713171), or open a new PR or Issue later today.

[harding]

NACK. I think this makes the critical opening section of the alert confusing and less effective. If we want to add technical details and background information, that should go at the end where it will not distract readers from seeing the import steps they should take to secure their funds.

In addition, this text contains several inaccuracies which I have commented on.

Further, I strongly object to @wbnns setting this post as default merge when several of these same issues were discussed separately on a different pull and he was unable to make his case persuasively there, as evidenced by the PR without these changes receiving several ACKs.

I request that this PR follow the normal process of waiting to receive ACKs from someone besides its author before being merged.

[harding]

"called Bitcoin Core". Not true; it used to be called just "Bitcoin". The name was changed in version 0.8 IIRC.

[wbnns]

I went ahead and just struck this part so we don't have to split hairs, I was just referring to it by its current name so people could reference if they'd like.

[harding]

"billions of transactions" Not true; its 238,962,626 transactions as of the most recent block, 00000000000000000176c021933ac22cfff38b4ac9ca4536e6aa7e8554dd8283

[wbnns]

My bad, I was looking at the wrong chart, total value of transactions - thanks for catching. Fixed.

[harding]

"... help propagate transactions" This is completely unrelated to the issue at hand.

[wbnns]

Struck help propagate transactions from the copy.

[harding]

"some nodes may propagate confirmed transactions that other nodes may not accept or recognize" this is a poor description of a problem that's less significant than the main problem. The main problem is that you will think you have bitcoins when you don't, and so you'll do things like trade real money, products, or services for bitcoins that have no value.

[wbnns]

The transactional risk ("main problem" that you mentioned) is already described in other places, so I think the additional descriptor in this PR should be left in to help explain to people who have voiced confusion over the previous version.

[wbnns]

@harding Hey, you're right, I did mention that we need an introductory paragraph yesterday before we went live, and since then there has been a lot of user feedback on places like Hacker News or Reddit where people are saying that they are confused about what is going on.

Thanks for the feedback on the other points though, I'm updating that now.

[wbnns]

Ok, updated. I think the chain split info should still go at the beginning. People are confused, for example, here is the most upvoted comment on Hacker News (this post is also one of the top trending items on Hacker News, now):

@harding It's important with this kind of update that we be aware of user feedback and try to make sure this post is as helpful as possible to users in a responsive way. The original post did not adequately do that as you can see if you go to Hacker News, Reddit or other social media.

[harding]

@wbnns given that you plan to merge over my NACK, I leave responsibility for this document in your hands both now and after August 1st. I've found it very difficult to work with you on this issue from the start and I think it's probably a waste of time for both of us to continue arguing.

[wbnns]

@harding Ok, no problem - as mentioned, you're welcome (as is anyone else) to submit a PR to my branch or open a new separate issue or PR. I'm also up for working on this to make any further revisions (in addition to the ones I just made based on your feedback).

The most important thing here is to make sure we're keeping this updated to help inform and protect users, since that's who this post is written for.

If we're not listening to their feedback when they're saying the initial version makes them confused then we're missing out on opportunities to improve it and to do our best to help them.

[achow101]

If you're going to include information about alternative clients causing a chain split, then you will need to mention BIP 91. I think just a brief mention that there is another proposal (BIP 91) that has the potential to activate and cause a chain split prior to august 1st, but it requires 80% hash rate to activate and there are currently no miners signalling for it. However 80%+ of the hash rate has verbally agreed to activate that proposal some time this month.

Could you also please wait for other people to review any changes to the page before merging? I would like to review them and I will try to review them as quickly as possibly.

[achow101]

confirmation scoring should be linked.

[wbnns]

I linked to it in the second paragraph, the first time it was mentioned:

[achow101]

There should be a comma between months and alternative.

[wbnns]

@achow101 Thanks, fixed. 👍

[achow101]

ACK 3fbea0c

[wbnns]

@achow101 Thanks for reviewing. With regard to adding a note about BIP 91, could you please open a separate PR with the content you have in mind once this gets merged?

The reason I think it is important to get the current PR live soon is because as already mentioned, a lot of people are confused. Also, at least 75,000 people are going to visit Bitcoin.org today and see the alert. In addition to people asking questions on Hacker News, Reddit and social media, the International Business Times just went to print with an article mentioning that this is a statement being made to everyone by Bitcoin Core developers:

...which this is not (fixed in f47370a). The Associated Press also reached out to clarify if this was a statement from Core developers.

Once tests pass I'm going to merge this, and if anyone would like any subsequent changes, please open an issue or PR. I will be standing by to help work together so we can make sure any subsequent changes get brought in so we can make this as good and comprehensive as possible for everyone who reads it.

[achow101]

@wbnns Ok. I will be making two PRs in the near future, one with BIP 91 information and the other with some general instructions on choosing a chain to use and splitting coins.

[wbnns]

@achow101 Ok, thanks for the help.