Here is my theory of #Reviewer2 – I’m curious to hear whether you find plausible!

It is commonly claimed that in any set of reviewers, #Reviewer2 is the really mean one. Here’s why:

You submit a paper to a journal. The journal uses an algorithm to assign reviewers. The algorithm is based on a comparison between the paper’s reference list and reference lists of published papers. It results in a ranked list of reviewers, with the best matches at the top. (1/4)

@academicchatter

Taking into account the typical “decline” response rate, at least 6 very suitable reviewers from the top of the list will be invited. These are busy people, so only one of them accepts the invitation. This is #Reviewer1, who will write a helpful and constructive review. (2/4)
People lower down on the ranked list, who are even less likely to accept, are invited to review. At some point, one of them will accept the review for reasons that have nothing to do with your paper (boredom, feeling guilty, bad day…). This is #Reviewer2, who will not like your paper and tell you that you must change absolutely everything in it – to turn it into a paper they would have liked to read. (3/4)

Next, the editorial office checks the status of your paper and finds out that only two reviewers have accepted the invitation although the journal policy requires three. They contact someone who owes them a favour or a member of their editorial board. This person will take only a quick glance at the paper and write a positive, but generic review. This is #Reviewer3.

So – what do you think of my theory?? (4/4)

@landwehr_c I feel like my papers have had the #Reviewer2 treatment from Reviewer 1, 2 or 3! The meme in my field is Reviewer 3 being the worst. I heard an explanation that Rev3 was the last to turn in their review and, having been hassled, were more grumpy. But I think there is a large random element here.
@steveroyle I totally agree that it's mostly random - I have been reviewer 1, 2 and 3! But I definitely write the best reviews when I'm really interested in a paper's topic and accept the invitation straightaway, while being hassled always makes me grumpy.