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  "name": "betbetter-margin-index",
  "description": "The Bet Better Margin Index: daily measured bookmaker margins (overround) by market class and shape, aggregated across 50+ bookmakers from 1 July 2026. Aggregates only; no prices or bookmaker names. Free to reuse with a credit to Bet Better (betbetter.world).",
  "url": "https://betbetter.world/studies/margin-index",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "citeAs": "Bet Better (2026). The Bet Better Margin Index. https://betbetter.world/studies/margin-index",
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  "datePublished": "2026-07-01",
  "isLiveDataset": true,
  "keywords": ["bookmaker margin", "overround", "sports betting", "market efficiency", "open data"],
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      "@id": "margin-index.csv",
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      "description": "Full daily series as CSV. Lines starting with # are comments.",
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