After a user requested their duplicate accounts be merged on Bio, I'm a little puzzled by their reputation.

Account A posted a question which at the time of merger had 2 upvotes, 1 downvote. I make this a net score of +10 -2 = +8. This should make that accounts total rep 9 including the mimimum value.

Account B at the time of merger had 3 answers, 2 deleted of which one had an upvote. Again by my reckoning that makes a total reputation of the minimum 1.

I would expect, therefore, that after the merge the user would have 9 rep as a result of 2 upvotes on questions, 1 downvote on questions. Yet the account actually has 11 rep. Whilst this is clearly a travesty of justice that needs to be fixed as the highest priority, I am interested as to what I'm missing here.

I guess it could either be:

  1. The downvote on the question, originally attributed to Account A wasn't moved to Account B but the upvotes were.
  2. The minimum rep of both accounts is transferred in the merger giving the extra +2. Don't see why this would happen though.

Just thought to check the reputation page (facepalm) and saw that the -2 entry for the downvote is indeed missing:

Missing downvote reputation screenshot

  • 3
    If the downvote happens before the upvote it never takes new users into negative rep. – Martin Smith May 20 '12 at 11:56
  • Ahh so the post merge recalc is done in chronological order? – Rory May 20 '12 at 11:58
  • I guess so, seems correct that merging should yield the same result as if the accounts had been one all along. – Martin Smith May 20 '12 at 12:02
  • 2
    @Rory Yeah, once the users are merged, all votes are processed in the same order they would've been if they were on one account to begin with. – Adam Lear May 20 '12 at 12:10

When two accounts are merged, the two reputation histories are merged as well. Each item is sorted by date. So it is as if all the events happened in order for one account. So since the downvote occurred before the upvote, when the user's rep was at one, it did not bring the user into negative rep or cancel out with the future-earned rep. So that downvote was not counted against that users reputation because, if we pretended that it was one account all along, it was before the upvotes, and could not bring the user negative.

So the reputation history looked like this:

  • -0 (downvote, but could not bring user negative) reputation: 1
  • +5 (upvote) reputation: 1 + 5 = 6
  • -5 (unupvote) reputation: 6 - 5 = 1
  • +5 (upvote) reputation: 1 + 5 = 6
  • +5 (upvote) reputation: 6 + 5 = 11
| improve this answer | |

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .