How Much Trouble Is Early Foul Trouble? Strategically Idling Resources in the NBA

We analyze a large and comprehensive play-by-play dataset of professional games in the National Basketball Association using tools from financial economics to explore the optimality of strategically idling resources in the face of uncertain future demand. We find that starters ought to be idled by the coach on a “Q+1” basis, meaning that a starter has one more foul than the current quarter, when the future option value is high or the value of the replacement player is high. We use a novel win-probability approach that can be easily extended to other applications.