http://hckrnews.com can be used to see which submissions reached the front page and then were marked [dead]. [dead] is distinct from [flagged] and can occur for administrative reasons. [flagged] means that enough users have flagged the story to penalize the ranking, but not to remove it.
http://hnrankings.info can indicate which submissions were [flagged] by enough users to be penalized. You'd be looking for sudden drops in ranking. Note though that the 'flamewar detector' (based on the number of comments to upvotes) can also cause sudden drops that can be hard to distinguish.
If you think your reasons for wanting this are well justified, consider writing a polite email to hn@ycombinator.com and asking if they would be willing to provide it. Personally, I think it would be an interesting analysis, although they may have legitimate reasons to keep the information private.
I don't recall the exact numbers anymore, but if you have a high number of comments relative to the number of upvotes early on, it gets automatically deprecated by the software. So, you get a few upvotes, it hits the front page, a bunch of people promptly post something, it falls off the front page, basically. The assumption is this is a fighty subject and the kind of conversation breaking out is not the kind they want to foster here -- or so I understand it, as someone who is just a member.
http://hnrankings.info can indicate which submissions were [flagged] by enough users to be penalized. You'd be looking for sudden drops in ranking. Note though that the 'flamewar detector' (based on the number of comments to upvotes) can also cause sudden drops that can be hard to distinguish.
If you think your reasons for wanting this are well justified, consider writing a polite email to hn@ycombinator.com and asking if they would be willing to provide it. Personally, I think it would be an interesting analysis, although they may have legitimate reasons to keep the information private.