We've merged quite a few! but not all, because (1) to some extent there are distinct ongoing subplots, and (2) it's too big a mess to control.
If you or anyone want to know how we handle this, here you go...
Once or twice a year, a Major Ongoing Topic (MOT) hits HN that isn't just one big story, but an entire sequence of big stories. A saga, even! This is one.
With these we can't do what we usually do, which is have one big thread, then treat reposts as dupes for the next year or so (https://news.ycombinator.com/newsfaq.html). Each development is its own new story and the community insists on discussing it. It's not a movie, it's a series. Sometimes there can be 3 or 4 episodes at once.
On the other hand, when this amount of shit hits this number of fans, there is inevitably a large (excuse me) spray of follow-up stories, as every media site and half the blogs out there rake in their share of clicks. These are the posts we try to rein in, either by merging them—hopefully into a submission with the best link—or by downweighting them off the front page.
The idea is to have one big thread for each twist with Significant New Information (SNI)—but to downweight the ones that are sneeless (pvg came up with that), the copycats and followups.
We came up with this strategy after the Snowden affair snowed us in in July 2013. Back then we weren't making the distinction between follow-ups and SNI, so the frontpage got avalanched by sneelessness on top of the significant new developments. It wasn't obvious what to do because (1) the story was important to the community and needed to be discussed as it was unfolding, but at the same time (2) it wasn't right for the front page to fill up with mostly-that, and there were complaints when it did.
The solution turned out to be just this distinction between follow-ups and SNI. It has held up pretty well ever since. Of course there are still complaints (and I do hear yours!) because not all readers are equally into the series. But the strategy is optimal if it minimizes the complaints, which (big lesson of this job -->) never reach zero.
If we pushed the slider too far the other way, we'd generate complaints about uncovered developments of the story, from readers with the opposite preference. They would in fact proceed to inundate HN with submissions about the bits that they feel are under-covered, and since we can't catch or filter everything, we'd end up with more duplicates and follow-ups on the frontpage, not less. It's like that paradox where building more highways gets you more congestion, or one of those paradoxes anyhow.
That's basically it! Past explanations for completists: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...