To better understand the characteristics of athletes who tend to underperform under pressure, we investigated how (a) working memory (WM) capacity and (b) responsiveness of the dopamine system shape real-life performance under pressure. We expected that athletes with smaller WM capacity or a more responsive dopamine system (as operationalized with a risk-taking measure) are especially prone to fail during decisive moments. In a sample of competitive tennis players, WM capacity was measured with the Automated Operation Span task (AOSPAN); responsiveness of the dopamine system was measured with a risk-taking measure, the Balloon Analogue Risk Task (BART). As expected, higher AOSPAN scores predicted better performance during decisive sets; higher BART scores predicted worse performance during decisive sets. These findings indicate that real-life tennis performance can be predicted from behavioral tasks that tap into WM functioning and risk taking, and suggest that the ability to effectively use WM despite pressure separates chokers from nonchokers.