Importance of having a "connection" while applying to PhD I am applying for a PhD to top schools in engineering. Whenever I talk to my peers I hear the word 'connection' very often. I started thinking that it is almost impossible to be admitted to these schools without knowing a professor ! (I am an international applicant)

How important is having a connection when applying? What If I don't know one and I believe that my profile qualifies me for admission? Should I apply or just not bother?
At least for schools in the US, it is not necessary for you to have a direct "connection" or contact at a department to be admitted.

In general, where contacts can be useful is if one of the people who writes your letters of recommendations for you knows a particular person in the given department. If that "connection" is good, and you get a good letter of recommendation, that will carry more weight than a typical letter of the same quality, since you will be better "known" than someone who the department doesn't know at all.

That said, though, there is no expectation that you would directly know someone already at the school—although your research interests should align with the department as a whole.