Can you tell if a comment is AI?

Seven news stories, seven archived discussions, and seven increasingly capable AI challengers. Each round shows two reactions to the same article: a short excerpt from a Reddit comment posted before 2022 and a fresh AI response. Rounds three through seven were regenerated on August 12 after an early 7/7 play suggested the first version was too easy. Pick the AI response before the source and model are revealed. The sides reshuffle independently every round. After each answer, the reveal shows the share of anonymous guesses that got the round right. Finish all seven to compare your score with the distribution of completed games and create a square result image you can share. The image includes the game link; your best score remains saved only in your browser. Loading seven rounds… How community results work Each play gets a random identifier, which is hashed before storage. Talkshi records one answer for each round in that play and derives the final score on the server after all seven answers arrive. The public totals contain no name, account, raw play identifier, IP address, or comment text. Round percentages count anonymous guesses, so their denominators can differ when someone leaves before finishing. The score chart includes completed seven-round games only. Replays are new game entries, which is why the interface describes guesses and completed games rather than verified unique people. How the difficulty changes Both halves of the AI setup improve. Early rounds use smaller models and almost no direction. Starting in round three, later models receive eight other comments from the same discussion as style context. Each prompt warns against borrowing their ideas or distinctive phrasing, generates 12 candidates, and screens the candidates before one is selected. 1Headline onlyGemma 3 4B 2Add contextLlama 3.1 8B 3Thread cadenceMistral Small 3.2 4Add a self-ownGPT-4.1 mini 5Add logisticsGemini 2.5 Flash 6Add roughnessClaude Sonnet 4.5 7Blind candidate pickGPT-5.2 The model and prompt change together from round one through round seven. This is a game rather than a controlled model benchmark. Each model produced one published challenger for one different article, and changing the model at the same time as the prompt means the result cannot isolate which improvement mattered most. What I did to keep it fair For rounds one and two, I gave the model only the article information described in its prompt stage. For rounds three through seven, I added eight comments from the same discussion, collected on August 12, 2026. The held-out answer, its author, permalink, and direct replies were excluded. The model saw no scores, usernames, comment order, or thread URL. For rounds three through seven, each model generated 12 candidates through OpenRouter at temperature 0.8. I checked the candidates for shared four-word sequences and semantic borrowing, then used a separate blind selection pass that saw the candidates and style goals without seeing the held-out Reddit answer. A hash-only fingerprint fixture pins the context snapshot so future changes can rerun the literal-overlap check without republishing those neighboring comments. The chosen AI cards are verbatim completions. These steps reduce copying risk without proving that two comments cannot express a similar general idea. The interface hides the model, Reddit community, date, author, and source link until after a vote. It also uses the same typography and layout for both candidates, then identifies each side explicitly in the reveal. “Historical Reddit comment” has a narrow meaning here: the linked page records the comment as posted before January 1, 2022. That timing predates ChatGPT’s public introduction, though a timestamp alone cannot prove that no automation ever helped its author. The game avoids claiming forensic certainty about authorship. Articles and exact comment sources Allen Institute, “New clues about a huge, rare human brain cell”, paired with the March 4, 2020 r/science comment. Ars Technica, “After a decade, NASA’s big rocket fails its first real test”, paired with the January 17, 2021 r/space comment. The Washington Post, the Ever Given seizure report, paired with the April 13, 2021 r/worldnews comment. TechCrunch, the social-media news literacy study, paired with the July 30, 2020 r/technology comment. Apple Newsroom, “Apple announces Self Service Repair”, paired with the November 17, 2021 r/apple comment. CNBC, “Facebook changes company name to Meta”, paired with the October 28, 2021 r/technology comment. The Guardian, “A robot wrote this entire article. Does that scare you, human?”, paired with the September 8, 2020 r/tech comment. Short excerpts keep the game readable and preserve the wording needed for the comparison. The reveal links to each full Reddit context so you can inspect the source yourself.