Bookmaker Margin Panel: Daily Measured Betting Margins Across 22 Leagues and Player-Prop Markets
Description
Bookmaker Margin Panel: a daily panel of measured bookmaker margins (overround/vigorish) across head-to-head, spread and totals markets, plus the first public measurements of player-prop margins. Aggregated from over 4 million recorded odds observations (2.7 million cleaned markets) across 52 bookmakers, 22 leagues and 15 sports, 29 June to 2 August 2026. To our knowledge this is the only openly published bookmaker margin panel: it quantifies the price of sports betting - the amount by which a market's implied probabilities exceed 100% - across sports, market types, licensing regions and time. FILES. Main panel (3,494 cells: day x league x region x market type x time-to-start bucket) and props panel (1,148 cells: day x league x region x prop market). Columns: snap_date (UTC date), sport (league key, e.g. baseball_mlb, soccer_epl), region (au / us / offshore_intl), market_type (h2h, spread, total; specific prop market in the props file), outcomes (2, or 3 for soccer-style h2h with the draw), time_to_start (bucketed hours to scheduled start), mean_margin_pct, n_markets (cells under 10 excluded), n_bookmakers. HEADLINE FINDINGS. Player props average a 7.93% margin - 66% more than main head-to-head markets (4.77%); to our knowledge the first public measurement of prop-market margins (699,733 two-sided prop markets). The market-type price ladder: h2h 4.77%, spreads 4.90%, totals 5.45%, three-way soccer h2h 7.67%, player props 7.93%. Margin has a term structure: it peaks 1-3 days before the start (5.23%) and compresses to 4.71% in the final six hours. Australian-licensed bookmakers average 5.25%, US-licensed 4.72%, offshore/international 4.55%. METHOD. For every pre-match market observation, all priced outcomes were converted to implied probabilities (1 / decimal odds) and summed; the excess over 100% is the margin. Two-way and three-way markets are held in separate cells. Excluded: in-play observations, implausible margins (suspended or near-settled prices), and betting exchanges (commission-based pricing is not comparable). Individual bookmakers are deliberately not identified: cells aggregate across all operators in a region (n_bookmakers reports how many), so no operator's prices or price patterns are recoverable - the files are irreversible statistics, not a data feed in any form. No odds, prices or individual market observations are included. Operator-level statistics are published in the accompanying study: https://betbetter.world/studies/bookmaker-margins Released under CC BY 4.0, free to use including commercially, with attribution to Bet Better (https://betbetter.world). Also available on Zenodo (DOI 10.5281/zenodo.21755380), OSF (DOI 10.17605/OSF.IO/Q8XHF) and B2SHARE (DOI 10.23728/b2share.8rwvn-zz892). Quarterly updates planned. This dataset contains no odds, no prices and no wagering data - aggregate statistics only. 18+. Most people lose money gambling.