On December 1, 2012, the New York Times reported that the National Basketball Association (NBA) fined the Spurs for “sending starters home”. The decision by Coach Popovich highlights those decisions of who plays and for how long is more complex than simply a measurement of the productivity of the players. Based on these events, two major questions come to light. The first is how the number of minutes played by players is determined. This productivity assessment will be addressed in Part I of this paper using data from both the NBA and WNBA. The second is whether playing decisions utilize the sunk cost fallacy, where salary is a determining factor in playing time. The aim of this study is not to be able to give concrete policy recommendations but rather to investigate the sunk cost fallacy phenomenon in professional sports. The results indicate an unexplained positive relationship between minutes and salary which lends affirmation that the sunk cost fallacy exists in the NBA.