13 companies where he completed the entire interview circuit. The further you get in an interview circuit, the more likely you are to continue, and thus to even

13 companies where he completed the entire interview circuit. The further you get in an interview circuit, the more likely you are to continue, and thus to eventually get an offer. Only getting offers from 50% of those might indicate you're doing something surprising towards the end, like coming across as a jerk to the skip-level+ the last interview is usually with.