Over the past 30-odd years, I guess I must have supervised around 20 PhD students and, I'm delighted to say, that none of the students that I supervised and who submitted a thesis have ever failed. Unfortunately, I didn't keep a list of students supervised and I don't know what all of them are doing now. I've always tried to work with and help develop students who were better than me and I'm delighted that some of them have gone on to be very successful in their careers.