This paper presents a study that investigates the role of confidence in predicting performance in a business strategy game (The Business Strategy Game, Thompson et al., 2022), specifically when making complex decisions as part of a team. The study distinguishes between an individual's confidence in their decision-making process and their confidence in specific decisions. Because complex business decisions are typically team-based, it also examines an individual's confidence in the team's decision-making process and actual decisions. Decision performance was measured two ways: financial performance (earnings-per-share) and non-financial performance (company image rating). Results show that an individual's confidence in their specific decisions positively predicts financial performance, whereas their confidence in the team's specific decisions positively predicts both financial and non-financial performance. Decision-makers consistently lost confidence in both their team’s decisions and decision process after receiving performance feedback but regained that confidence before the next decision. However, this pattern was less evident for an individual’s confidence in their own decisions or process. Over time, individuals gained confidence in their own decisions, the team’s decisions, and the team’s decision process, but this gain was not evident for confidence in the decision process.