# Investigating whether LLMs disproportionately use "spine" in GitHub pull request titles

DevFeed: [Investigating whether LLMs disproportionately use "spine" in GitHub pull request titles](<https://devfeed.tech/articles/the-llms-yearn-for-the-spines-32318.md>)

Original publisher: [Read original article](<https://buttondown.com/hillelwayne/archive/the-llms-yearn-for-the-spines/>)

Author: Hillel Wayne

Published: 2026-09-16T19:58:30Z

Content type: opinion

Language: en

Sources: [Newsletter feed for Hillel Wayne's Newsletter](<https://devfeed.tech/sources/newsletter-feed-for-hillel-wayne-s-newsletter.md>)

Topics: [Large Language Model](<https://devfeed.tech/topics/llm.md>), [Artificial Intelligence](<https://devfeed.tech/topics/ai.md>), [GitHub](<https://devfeed.tech/topics/github.md>), [pull-requests](<https://devfeed.tech/topics/pull-requests.md>), [anthropic](<https://devfeed.tech/topics/anthropic.md>), [cursor](<https://devfeed.tech/topics/cursor.md>)

Tags: [2026](<https://devfeed.tech/tags/2026.md>), [ai](<https://devfeed.tech/tags/ai.md>), [claude](<https://devfeed.tech/tags/claude.md>), [cursor](<https://devfeed.tech/tags/cursor.md>), [github](<https://devfeed.tech/tags/github.md>), [llms](<https://devfeed.tech/tags/llms.md>), [pull-requests](<https://devfeed.tech/tags/pull-requests.md>)

## AI overview

The article investigates whether large language models disproportionately use the word "spine" in GitHub pull request titles. Using GitHub Search as a proxy, it finds a much larger increase in "spine" pull requests than overall pull requests, but does not establish that the pattern comes from one specific model; sampled pull requests were coauthored by Claude or Cursor.

## Source excerpt

Earlier this year I worked on a couple of AI-generated TLA+ specifications, and one thing I've noticed was that they all used the word "spine" somewhere. Then I saw some non-TLA+ public projects use "spine" too and got curious if it was a new LLMism (LLisM?). If it is, we should see it appear in a discontinuous jump in the number of code projects that use "spine". The proper way to thoroughly explore this would be via the GitHub archive data dump but that'd take forever and I have a full time job now. Instead, I'm going to use GitHub Search. We can't filter code samples by date but can filter pull requests, which seems like an acceptable enough proxy. Here's a graph of the number of public PRs each year with "spine" in the title: I stopped 2026 at 2026-09-01, meaning the first nine months of this year have seen 20 times more "spine" PRs as all of 2025. Now it could be the case that that GitHub grew, like, a lot in the last year. Maybe the 20x increase is due there being 20x as many pull requests. We can account for this by comparing it against all public PRs:1 If "spine" wasn't an LLisM, we would expect only a 1.5xish increase from 2025, not a 20x increase. One other possible confounder could be that LLMs don't like the word spine but PRs Georg submitted 15,000 changes to a chiropractor repo. I will deal with this issue by ignoring it. Can we figure out which models specifically are obsessed with spines? Let's try breaking the change down by month: Looking at LLM timeline, the only widely-used model released in May was Opus 4.8, which came out too late in the month to explain the spike. GPT 5.5 came out in April, which could be the cause. But I'm not convinced by this. For one, the spine count is still 1.5xing each month before April, and I definitely remember seeing spines as early as February. Also, I spot checked and many of the PRs that use "spine" are coauthored by Claude or Cursor. So I think it's not specific to one LLM, but could be convinced otherwise. Othe