The development of performance, such as learning a new motor skill, can be represented in a performance curve. The shape of the performance curve is both of theoretical and practical relevance. Here, the author studied the interday performance of juggling over a period of 17 days in 112 college students. The results showed that 60% of participants followed an S-shaped performance curve with the inflection date on the 11th day, followed by a decelerated (20%), accelerated (14%), and linear curve (6%). As expected, except on Day 1, male participants performed at least 33% better than female participants on each practice day. Also as expected, learning performance was found to depend on the type of performance curve with the best learning performance exhibited by the linear group. The results further revealed that pooling all participants' performance together without considering the percentage of each underlying type of performance curve would lead to biased, nonrepresentative results. Given the variety of the observed performance curves and the dominance of the S-shaped performance curve among them, coaches should continuously monitor the shape of an individual's performance curve.