This paper examines results of a flexible grading system that allows each student to influence the weight allocated to each performance measure. We construct a stylized model to determine students' optimal responses. Our analytical model predicts different optimal strategies for students with varying academic abilities: a frontloading strategy for those with high academic ability and a gambling strategy for others. We test the model using data gathered from several sections of an Intermediate Accounting course offered by a Canadian university. We find that most students did make decisions that were consistent with our analytical model. Our results suggest that the flexible evaluation system does not uniformly motivate students of differing abilities and does not encourage most students to maintain effort uniformly throughout the semester.