In this paper, we sought to understand what the reasons are for why athletes' performance fluctuates, so that we could learn how to improve our overall performance in our respective sports. Previous research has predicted athletic performance consistency by variables such as anxiety, mental conditioning, and confidence. In our first (correlational) study, we tested the strength of these relationships by examining naturalistic daily changes in their variables longitudinally over a one-week period. We measured anxiety, focus, and confidence each on a zero to ten scale, and measured performance consistency by recording our basketball shot attempts in comparison to shot makes. Based on the strength of correlation found between mental conditioning and performance consistency in our correlational study, we then conducted a second (experimental) study to test for a causal relationship between these two variables. Over a one-week period, we assigned participants on alternate days to either a focused condition or an unfocused condition and measured the effect this manipulation had upon mental conditioning. Data pooled across participants in our correlational study showed that performance consistency was associated with mental conditioning and confidence, but not with anxiety. Data pooled across participants in our experimental study failed to establish a causal role of mental conditioning upon performance consistency.