Previous research on sports leagues has shown that uncertainty of outcomes is an important driver of attendance, viewership and overall public interest in sports leagues. Competitive balance in a sports league is a measure of the degree of uncertainty of outcomes of sporting events in that league. Thus, it is important to measure and quantify competitive balance. This research generalizes several measures of competitive balance from head-to-head sports and applies them to National Association for Stock Car Auto Racing (NASCAR). Included are discussions of the Herfindahl-Hirschman Index, concentration ratios, idealized standard deviation, and churn. I explore several definitions of “winning” in NASCAR to see how these definitions affect measures of competitive balance, and find that the definition of winning has a large impact on how competition is measured. In addition, I show the rationale and importance of normalization on these measures.