How can we explain why professional basketball teams win? Is it the coach, the players, or just the numbers? This research project was intended to answer these 2 questions: 1. In the 2004 NBA season, what was the relationship between winning percentage and 11 statistical factors: field goal percentage, team defense, three point percentage, scoring per game, free-throw percentage, steals per game, turnovers per game, blocks per game, offensive and defensive rebound margin, and total rebound margin? 2. Which of the statistical factors examined in the study was the most influential in determining winning percentage in 2004? Basketball is becoming more of a science. This subjective information on coaching decision and knowledge has turned to descriptive data for answers to why teams win. This study provides information that will be valuable to coaches, basketball analysts, and other consumers of the game.