Purpose

Professional sports teams employ highly paid managers and coaches to train players and make tactical and strategic team decisions. A large literature analyzes the impact of manager decisions on team outcomes. Empirical analysis of manager decisions requires a quantifiable proxy variable for manager decisions. Previous research focused on manager dismissals, tenure on teams, the number of substitutions made in games or the number of healthy players on rosters held out of games for rest, generally finding small positive impacts of manager decisions on team success.

Design/methodology/approach

The authors quantify manager decisions by developing a novel measure of game-specific coaching decisions: the Herfindahl–Hirschman Index (HHI) of playing-time across players on a team roster over the course of a season.

Findings

Evidence from two-way fixed effects regression models explaining observed variation in National Basketball Association team winning percentage over the 1999–2000 to 2018–2019 seasons show a significant association between managers’ allocation of playing time and team success. A one standard deviation change in playing-time HHI that reflects a flattened distribution of player talent is associated with between one and two additional wins per season, holding the talent of players on the team roster constant. Heterogeneity exists in the impact across teams with different player talent.

Originality/value

This is one of the first papers to examine playing-time concentration in the NBA. The results are important for understanding how managerial decisions about resource allocation lead to sustained competitive advantage. Linking coaching decisions to wins can help teams to better promote this core product.

中文翻译：

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运动队的成功和管理决策：比赛时间集中度的作用

目的

职业运动队聘请高薪经理和教练来训练球员并做出战术和战略团队决策。大量文献分析了经理决策对团队成果的影响。管理者决策的实证分析需要管理者决策的可量化代理变量。之前的研究主要集中在主教练的解雇、球队的任期、比赛中的换人次数或名单上健康球员的数量而没有参加比赛休息，通常发现主教练的决策对球队成功的积极影响很小。

设计/方法论/途径

作者通过开发一种针对特定比赛的教练决策的新颖衡量标准来量化经理的决策：赫芬达尔-赫希曼指数（HHI），衡量球队名单上球员在一个赛季中的上场时间。

发现

双向固定效应回归模型的证据解释了 1999-2000 赛季至 2018-2019 赛季观察到的国家篮球协会球队获胜率的变化，表明经理人的上场时间分配与球队成功之间存在显着关联。上场时间 HHI 的一个标准差变化反映了球员天赋分布的平坦化，与每个赛季一到两场额外的胜利相关，从而保持球队名单上球员的天赋不变。不同球员天赋的球队之间的影响存在异质性。

原创性/价值

这是最早研究 NBA 比赛时间集中度的论文之一。研究结果对于理解资源分配的管理决策如何带来持续的竞争优势非常重要。将教练决策与胜利联系起来可以帮助团队更好地推广这一核心产品。