Two consecutive titles on the HN front page yesterday had a 6 in them. This means nothing . But it’s the sort of nothing that lodges in your brain until you do something about it, so what is the most popular number in Hacker News titles? ClickHouse hosts the full HN dataset in their public playground , and I am exactly the kind of person who finds that exciting. The obvious query is barely a query at all: SELECT num , count () AS c FROM ( SELECT arrayJoin ( extractAll ( title , ' \d +' )) AS num FROM hackernews_history WHERE type = 'story' AND title != '' ) GROUP BY num ORDER BY c DESC LIMIT 10 Number Titles 2 119,351 3 114,397 1 114,017 5 82,066 4 63,482 0 60,931 10 50,534 6 38,440 7 37,261 8 37,190 The most popular number in HN titles is 2. Case closed, post over . But why are the numbers so small? That’s the Vsauce jingle. This post is about to become ‘but why is 19 like that’.…