Line Movement Dataset: how much betting lines actually move (11.7M odds snapshots)

Aggregate measurements of pre-match betting line movement across 13+ sports and three market types, built from 11.7 million odds snapshots recorded at roughly hourly cadence across 52 online bookmakers and 22 competitions, 29 June – 3 August 2026. To our knowledge the first open, multi-sport measurement of line movement magnitude. Files: (1) betbetter_line_movement_h2h.csv — open-to-close movement of de-vigged head-to-head probabilities, one row per sport, including the signed drift of the opening favourite; (2) betbetter_line_movement_points.csv — movement of the quoted spread/total line itself, one row per sport × market type; (3) betbetter_distance_to_close.csv — mean absolute gap to the closing price by sport × time-to-start bucket. Headline findings: movement is sport-specific by an order of magnitude — UFC/MMA lines move 2.76 probability points open-to-close (53% move >2 pts), AFL 2.52, WNBA 1.81, against MLB 0.60. Price discovery happens 1–7 days out: prices sit ~2.2 pts from their close 3–7 days before start but only 0.33 pts in the final six hours. Favourites systematically shorten toward the close (MMA +0.8 pts). AFL handicaps move 2.55 pts with 76% of lines changing, while MLB run lines are essentially static. Probabilities are de-vigged before measurement, so figures reflect price relocation, not margin change. Aggregates only: no odds, prices, bookmaker identities, teams, players or event identifiers; no underlying feed can be reconstructed. CC BY 4.0. Companion study: https://betbetter.world/studies/line-movement. Related: Bookmaker Margin Panel (doi:10.5281/zenodo.21755380), Market Calibration Dataset (doi:10.5281/zenodo.21764674).本数据集收录了13项及以上体育运动、三类市场类型的赛前盘口变动聚合测算结果，数据源自52家在线博彩运营商、22项赛事中以约每小时一次的频率采集的1170万条赔率快照，采集时段为2026年6月29日至8月3日。据我们所知，本数据集是首个公开的多运动项目盘口变动幅度量化数据集。 文件包含：(1) betbetter_line_movement_h2h.csv：收录去佣金（de-vigged）后的对阵胜负盘（head-to-head）概率从开赛初到收盘的变动情况，每条记录对应一项运动，包含初始热门方的带符号漂移量；(2) betbetter_line_movement_points.csv：收录报价让分盘/总分盘的变动情况，每条记录对应一项运动×市场类型组合；(3) betbetter_distance_to_close.csv：收录按运动项目×开赛倒计时时段划分的平均绝对收盘价差。 核心研究结论显示：盘口变动幅度存在显著的项目特异性，差异可达一个数量级——UFC/MMA盘口的概率变动幅度为2.76个百分点（53%的盘口变动超过2个百分点），AFL为2.52个百分点，WNBA为1.81个百分点，而MLB仅为0.60个百分点。价格发现过程集中在开赛1至7天前：开赛3至7天前，赔率与最终收盘赔率的平均差距约为2.2个百分点，但开赛最后6小时内该差距仅为0.33个百分点。热门方赔率在收盘阶段系统性收窄（MMA项目变动幅度为+0.8个百分点）。AFL让分盘变动幅度达2.55个百分点，76%的盘口发生变动，而MLB的棒球让分跑线（run lines）基本无变动。 测算前已对概率进行去佣金处理，因此相关数值反映的是赔率本身的迁移，而非博彩运营商佣金的变化。本数据集仅提供聚合数据，不包含原始赔率、具体报价、博彩运营商身份、参赛队伍/选手信息或赛事标识符，无法还原原始数据源。本数据集采用CC BY 4.0协议开源。配套研究链接：https://betbetter.world/studies/line-movement。相关数据集包括：博彩运营商佣金面板数据集（Bookmaker Margin Panel，doi:10.5281/zenodo.21755380）、市场校准数据集（Market Calibration Dataset，doi:10.5281/zenodo.21764674）。