How Hacker News ranking works: scoring, controversy, and penalties (2013)
- ID
- 26510
- Status
- summarized
- Published
- 20 Sep 2026, 5:30 AM
- Fetched
- 21 Sep 2026, 8:53 PM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://www.righto.com/2013/11/how-hacker-news-ranking-really-works.html
- Source URL
- https://hnrss.org/best
Summary
- Score
- 6.0
- Created
- 21 Sep 2026, 9:58 PM
- Tags
- Audience
- developersvibe_coders
What happened
Ken Shirriff analyzed the top 60 Hacker News stories over several days and confirmed the published ranking formula is mostly accurate, but found that ~20% of front-page stories receive invisible penalties. Stories with 'NSA' in the title were penalized (later edited to note this was removed), and stories hitting 40 comments get severely penalized as 'controversial.' The time exponent (gravity) is larger than the vote exponent, so scores decay to zero over time. Reranking is lazy: stories only re-sort on upvote, plus one random top-50 story is reranked every 30 seconds, and pages can be cached for 90 seconds.
Why it matters
If you submit content to HN or any vote-based aggregator, understand that controversy (high comment count relative to upvotes) actively suppresses your post, and that a story can sit at a stale rank for minutes if it stops getting votes. For anyone building a ranking or feed system, the lazy-rerank-plus-random-perturbation approach is a concrete, battle-tested efficiency pattern worth knowing.
Discussion angle
The lazy reranking strategy (only re-sort on vote + random top-50 every 30s) is a pragmatic engineering choice — discuss whether this pattern applies to your own feed/search ranking systems and what tradeoffs it introduces.