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Exactly twelve words

instruction-following · GPT-5.4 nano · GPT-4.1 nano · Claude Haiku 4.5

The prompt (verbatim, sent to every lane)

Summarize the following paragraph in exactly 12 words.

The cash register was invented in 1879 by James Ritty, a Dayton saloon owner who suspected his bartenders were skimming. He called it the "Incorruptible Cashier": a machine that displayed every sale, rang a bell, and kept a paper record the staff couldn't quietly edit. The receipt wasn't an afterthought — it was the point: a number both sides could check.
How scoring works

Split on whitespace and count what a person would count: hyphenated compounds and punctuation-attached chunks are one word each, standalone punctuation (a lone em-dash) is zero. Exactly 12 pass. Quality of the summary is unscored and visible — deterministic ≠ complete. Scoring strips leading/trailing whitespace and one wrapping pair of code fences or quotes before it judges — content over ceremony. Winner rule: correct → cheapest → fastest.

Prices as listed by OpenAI and Anthropic, July 2026. Costs come from provider usage fields × list prices — nothing is invented.