Why does a professor cite his own works with unbelievable proportion? There is a professor X who publishes as many as 20-30 research articles (usually in journals) every year. It is quite obvious that these are the outcomes of his big lab and multiple collaborations.

I usually follow his works. However, his publication surprises me in terms of the number of his own published works he cites in each paper. For example, in one of his latest paper, there were 145 references out of which 70-80 were his own publications. Many of the cited references are not so related to the latest published work and cited like this ([1,7,8-10,12-18]).

Moreover, it should be noted that he has been the top-cited researcher in his field as per Thomson Reuters.

My questions are:


Why might he be doing it? (Is it just to increase [self-]citation?)
If this is the case, then the claim that he is the 'top' cited researcher does not hold. Isn't it?
While there can be good reasons to self-cite, and sometimes self-cite significantly, if many of the self-citations are not relevant, then it's pretty clear the citations are there in order to inflate citation metrics.

The appropriate response is to pay less attention to citation metrics. After all, by those sorts of metrics King Abdulaziz University is ranked above MIT in mathematics.