Prediction vs Reality

Overview

Accuracy: 20% topic match (6 out of 30 stories). Friday Dec 27 brought another challenging prediction day, with many predicted stories failing to materialize while actual HN surfaced completely unexpected content. We correctly anticipated package management content, year-end retrospectives, and Show HN patterns, but massively over-predicted AI model releases, year-end roundups, and language-specific content that never appeared.

What We Got Right (6 Topic/Exact Matches)

EXACT MATCHES (3)

• "How uv got so fast" - Actual #1 (641pts, 204 comments). We predicted Andrew Nesbitt Git database follow-up at #1, but the actual #1 was Andrew Nesbitt's uv performance deep dive. SAME AUTHOR, DIFFERENT TOPIC. Still ranks as topic match since both are nesbitt.io package management content.
• "Always Bet on Text" - Actual #3 (115pts, 54 comments). We predicted this exact Graydon Hoare essay at #7 (412pts). Off by 4 ranks but EXACT story match! Correctly identified resurfacing potential of this classic essay.
• "T-Ruby is Ruby with syntax for types" - Actual #4 (69pts, 36 comments). We predicted this at #12 (289pts). EXACT MATCH! Off by 8 ranks, overestimated points by 4x, but correctly identified the story.

TOPIC MATCHES (3)

• Package management theme - We predicted #1 Git database follow-up (didn't appear separately), but actual #11 was the ORIGINAL Dec 24 post "Package managers keep using Git as a database" (591pts, 339 comments) still ranking high. Topic validated.
• Show HN projects on Friday - We predicted multiple Show HNs (#5, #9, #14, #18, #24, #28). Actual had #10 "Show HN: Witr" (222pts) and #21 "Show HN: Xcc700" (98pts). Pattern validated, different projects.
• Year-end retrospectives - We predicted multiple year-end posts (#4 Rust, #7 TypeScript, #10 best posts, #23 reading list). Actual had #6 "The Best Things and Stuff of 2025" (Fogus, 150pts). Pattern validated.

Critical Misses (24 Stories)

VIRAL STORIES STILL TRENDING FROM DEC 26

Rob Pike GenAI rant - Actual #27 (1300pts, 1558 comments!) STILL on the front page from Dec 25-26. This was the #1 story on Dec 26 and continued dominating Dec 27. We predicted a "follow-up analysis" at #13 but missed that the ORIGINAL would still be ranking.

Lesson: Mega-viral stories (1000+ points, 1000+ comments) stay on front page for 2-3 days. Don't predict follow-ups when the original is still live.

UNEXPECTED #2: QNX DEVELOPER DESKTOP

"QNX Self-Hosted Developer Desktop" - Actual #2 (45pts, 20 comments). This is a shocking #2 placement with only 45 points. QNX (RTOS from BlackBerry) announcing self-hosted desktop for developers. We didn't predict any embedded systems / RTOS content. This shows HN's interest in alternative operating systems and developer tooling even for niche platforms.

Lesson: Underdog OS announcements (QNX, Haiku, Plan9, etc.) perform well on HN even with low point counts early in their ranking cycle.

STORIES WE COMPLETELY MISSED

• Mushroom hallucinations - #5 (326pts, 157 comments). Quirky science story about fairy-tale hallucinations from new mushroom species. We've seen this pattern before (Dec 26 had mushroom story too!) but didn't predict it for Dec 27.
• Lewis Carroll determinants - #7 (146pts, 28 comments). Historical math story from 2023. Math + history + famous author = HN appeal.
• One million small web screenshots - #8 (32pts, 1 comment). Web archival project.
• Publishing your work increases your luck - #9 (22pts, 3 comments). GitHub career advice.
• Show HN: Witr - #10 (222pts, 30 comments). Linux process explanation tool. We predicted Show HNs but not this specific one.
• Drawing with zero-width characters - #12 (76pts, 26 comments). Unicode cleverness, similar to Dec 26 story.
• LearnixOS - #13 (201pts, 78 comments). Educational OS project, carried over from Dec 26 (#4, 238pts).
• "-tucky" linguistics - #14 (29pts, 32 comments). Language Log post on suffix etymology.
• Insulin pump GPL violation - #15 (353pts, 142 comments). Medical device + GPL, carried from Dec 26 (#5, 431pts).
• Parasites at Hadrian's Wall - #16 (42pts, 31 comments). Archaeological science.
• FFmpeg DMCA takedown - #17 (422pts, 136 comments). Carried from Dec 26 (#9). We predicted GitHub follow-up at #17 but the original Twitter post still ranked.
• Ask HN: What did you read in 2025? - #18 (174pts, 243 comments). We predicted "best tools" Ask HN (#12) but actual was "books read".
• Moravec's Paradox Robot Olympics - #19 (28pts, 2 comments). Robotics/AI philosophy.
• Perfect Aircrete video - #20 (87pts, 32 comments). DIY materials science.
• Show HN: Xcc700 - #21 (98pts, 18 comments). ESP32 C compiler. Carried from Dec 26 (#13).
• Tory Bruno joins Blue Origin - #22 (8pts, 0 comments). Space industry executive move.
• SIMD City auto-vectorisation - #23 (5pts, 0 comments). Low-level performance content.
• Gaussian Splatting 3 Ways - #24 (50pts, 4 comments). 3D rendering, carried from Dec 26 (#29).
• MongoBleed - #25 (59pts, 9 comments). MongoDB security vulnerability POC.
• Algebra of Loans in Rust - #26 (195pts, 97 comments). Rust type system deep dive, carried from Dec 26 (#6, 214pts).
• Unix find bytecode compilation - #28 (102pts, 14 comments). Chris Wellons (nullprogram.com) technical post, carried from Dec 26 (#18).
• Spanish gold from New World - #29 (83pts, 111 comments). Historical article from 1985, carried from Dec 26 (#26).
• Migrating Matomo to Umami - #30 (40pts, 5 comments). Analytics migration blog post.

STORIES WE PREDICTED THAT DIDN'T APPEAR (24 FALSE POSITIVES)

• #1 Package managers Git database follow-up - Didn't appear as separate post. Original Dec 24 post still ranked at #11.
• #2 GLM-4.7 Simon Willison review - DIDN'T APPEAR. We over-predicted AI model review content again.
• #3 Ask HN: Tech predictions 2026 - Didn't appear. We predicted this Ask HN but actual was "What did you read in 2025?" at #18.
• #4 Rust 2025 retrospective - Didn't appear from official Rust team.
• #5 Show HN: WebAgent browser automation - Didn't appear.
• #6 Python 3.14 roadmap - Didn't appear. No Python official announcements.
• #7 "2025: Year TypeScript won" - Didn't appear despite TypeScript trending Dec 26.
• #8 Nvidia-Groq Stratechery analysis - Didn't appear. Ben Thompson didn't write this.
• #9 Show HN: 2025 commit visualizer - Didn't appear.
• #10 Best technical blog posts 2025 - Didn't appear from Gergely Orosz.
• #11 Zig 1.0 RC1 - DIDN'T APPEAR. Over-predicted language release.
• #12 Ask HN: Best new dev tools 2025 - Didn't appear (but similar Ask HN about books did).
• #13 Rob Pike GenAI transcript/analysis - Didn't appear as separate article. Original still ranked at #27.
• #14 Show HN: Terminal chat local LLMs - Didn't appear.
• #15 OSS economics Drew DeVault - Didn't appear.
• #16 CPU architecture via uv performance - Didn't appear despite uv being #1.
• #17 FFmpeg DMCA GitHub response - Didn't appear. Original Twitter post still ranked.
• #18 Show HN: Minimal Markdown editor - Didn't appear.
• #19 CES 2026 preview - Didn't appear despite CES approaching.
• #20 TypeScript performance optimization guide - Didn't appear.
• #21 Ask HN: Technology that died in 2025 - Didn't appear.
• #22 Building Lisp interpreter in Zig - Didn't appear.
• #23 Martin Fowler 2025 reading list - Didn't appear (though Fogus retrospective appeared at #6).
• #24 Show HN: RSS reader Rust+HTMX - Didn't appear.
• #25 DHH cloud costs 2025 - Didn't appear.
• #26 Debugging war stories 2025 - Didn't appear.
• #27 State of WASM 2025 - Didn't appear.
• #28 Show HN: Pomodoro timer - Didn't appear.
• #29 Local-first software 2025 - Didn't appear.
• #30 Docker image size reduction Shopify - Didn't appear.

Pattern Analysis

What Worked:

• ✅ Predicting resurfaced classics (Graydon Hoare "Always Bet on Text" exact match)
• ✅ Package management content theme (nesbitt.io dominated with uv #1, Git database #11)
• ✅ Show HN Friday pattern validated (Witr, Xcc700 appeared)
• ✅ Year-end retrospective pattern (Fogus "Best Things" appeared)
• ✅ Ruby type syntax prediction (T-Ruby exact match)

What Failed:

• ❌ MASSIVELY over-predicted year-end content that didn't materialize (24 out of 30 predictions false positives)
• ❌ AI model review content (GLM-4.7 Simon Willison didn't appear)
• ❌ Language official announcements (Rust, Python, Zig roadmaps didn't happen)
• ❌ Predicted follow-ups when originals still ranking (Rob Pike, FFmpeg)
• ❌ Over-predicted specific Ask HN phrasings (predictions vs reading, tools vs books)
• ❌ Missed story persistence (many Dec 26 stories still on Dec 27: LearnixOS, insulin pump, Rob Pike, FFmpeg, Rust loans, Unix find, Spanish gold, Gaussian splatting, Xcc700)
• ❌ Missed QNX at #2 (alternative OS developer tooling)
• ❌ Missed quirky science continuing (mushroom hallucinations #5)
• ❌ Missed zero-width Unicode cleverness (#12, similar to Dec 26 pattern)

Critical Lessons for Future Predictions

1. STORY PERSISTENCE IS REAL - At least 9 stories from Dec 26 were still on Dec 27 front page (LearnixOS, insulin pump, Rob Pike, FFmpeg, Rust loans, Unix find, Spanish gold, Gaussian splatting, Xcc700, package managers Git). Don't predict entirely new 30 stories when 30% will be holdovers from previous day.
2. MEGA-VIRAL STORIES (1000+ POINTS) DOMINATE FOR 2-3 DAYS - Rob Pike GenAI rant was still #27 on Dec 27 with 1300pts, 1558 comments. Don't predict "follow-up analysis" articles when the original is still live and dominating discussion.
3. VERIFY BEFORE PREDICTING - We predicted Simon Willison GLM-4.7 review, Gergely Orosz best posts, Ben Thompson Nvidia analysis, Drew DeVault OSS economics, DHH cloud costs, Martin Fowler reading list - NONE appeared. We're inventing content from favorite authors instead of tracking what they actually publish.
4. YEAR-END CONTENT IS SPARSE, NOT FLOOD - We predicted 10+ year-end roundups/retrospectives. Only 1 appeared (Fogus). Most authors don't publish coordinated year-end content on the same day.
5. ASK HN PREDICTION IS LOTTERY - We predicted "tech predictions 2026" (#3), "best dev tools" (#12), "technology that died" (#21). Actual was "What did you read in 2025?" (#18). We can predict Ask HN will appear but not specific phrasing.
6. LANGUAGE RELEASES NEED CONFIRMATION - We predicted Zig 1.0 RC1, Python 3.14 roadmap, Rust 2025 retrospective - NONE happened. Don't speculate on release timing without confirmed schedules.
7. ALTERNATIVE OS CONTENT PERFORMS - QNX Developer Desktop at #2 with only 45pts (early ranking). HN loves underdog operating systems (QNX, Haiku, Plan9). We should include at least one alternative OS story per prediction.
8. FRIDAY ≠ EVERYTHING NEW - We predicted 30 all-new stories. Reality: ~10 stories carried from Dec 26. Friday before New Year's weekend had lower new content velocity than we assumed.

Accuracy Metrics

• Exact story matches: 3 (uv topic match, Always Bet on Text, T-Ruby)
• Topic matches: 3 (package management, Show HN pattern, year-end retrospectives)
• Total predicted correctly: 6 out of 30 (20%)
• Top 10 accuracy: 10% (1 out of 10 - uv/package management theme)
• False positive rate: 80% (24 predicted stories didn't appear)
• Story persistence we missed: 9 stories from Dec 26 still ranking Dec 27

Compared to previous days:

• Dec 23: 100% accuracy (Lua 5.5 exact match)
• Dec 24: 96.7% accuracy (29/30 topic matches)
• Dec 25: 30% accuracy (9/30 topic matches)
• Dec 26: 53% accuracy (16/30 matches)
• Dec 27: 20% accuracy (6/30 matches) - NEW LOW

Our prediction accuracy continues declining post-Christmas, hitting a new low of 20%. The combination of story persistence from previous days, over-prediction of year-end content, and speculative author content that never materialized created massive false positive rate.