I am a graduate student focused on a subdivision of theoretical physics. When I am browsing papers, I find out an interesting case about the author's name ranking:
Let's assume there is a professor A (tenured) and B is a Ph.D. student supervised solely by A (which means there is no co-advising). There are plenty of published papers where the author list is made by only A and B. In my previous understanding, the first author is often given to the student(s) and the professor can be safely placed on the last of the author list to claim the achievement, as long as the professor acts as the corresponding author. However, the reality is that A is placed in front of B among most of their published papers (so the author list is: [A, B]), except for one paper where there are some other collaborators (i.e. [B, X1, X2..., A]).
I can't help figuring out the motivation for a professor to claim the first authorship over his own student. One of the reasons I could imagine is that student B cannot come up with meaningful research ideas or cannot carry out research independently. However, B has published X papers with A already (X>3) in some high-impact journals, and B's personal publication record is also promising (has more than 10 publications).
Can anyone share their thoughts about this situation? I have never seen such an interesting and unique case for the authorship arrangement.