What can one infer if more number of reviewers were assigned compared to the standard? [duplicate]

Question

If we submit a research paper to a journal in Elsevier, then the status will be 'with editor' for some time. Later, the editor invites reviewers. The number of reviewers depends on the manuscript and in general 3 according to Elsiver. After inviting the reviewers, the status changes to 'under review'.

How many reviewers are assigned to a manuscript?

The number of reviewers often varies by manuscript type. Most papers receive feedback from three peer reviewers. Shorter papers, such as brief reports or current issues, may receive feedback from two peer reviewers. Some journal submissions such as commentaries and book reviews are reviewed by AJPM editors and do not undergo external peer review

When Elsevier provides the tracking link, it mentions a field Review invitations sent. If it says more reviewers than the recommended then what can one infer from that?

Suppose my paper is assigned six reviewers then can I need to infer that my paper is complex enough that need more reviwers?

Answer 1

The editor can send extra invitations. If 3 are required, it is not entirely clear that 3 out of X will answer, some will reject. I caution it's generally bad form to send huge volumes of requests, but an occasional exceedence is not terrible (for example, if you need 2 reviewers, asking 3 at the start strikes me as very reasonable). It is not uncommon for reviewers to reject an invitation (depending on journal prestige), so one would not want to "waste" acceptances or tarnish the journal's reputation by putting massive burdens on authors to respond to N+ reviewers.

I note this is particularly common as far as the filing system that tracks this information is concerned. If reviewers do not properly select "reject" then it may be the case that there invitation is still 'outstanding' though it is clear that they will not review.

Answer 2

I don't think you can conclude anything without actually asking (and you may not get an answer). It depend on the paper and where it fits in the general literature at the time it is submitted.

I suspect that if you were to provide a paper yielding a definite conclusion to the Riemann Hypothesis that it would be sent to something like 20 or more reviewers. Probably more.

Something like this actually happened not long ago, though I don't remember the details. It was, like Riemann's Hypothesis, a long standing and important question. Perhaps someone still active in math can give a reference.