Objective: Neuropsychological baseline testing of athletes has become commonplace in the assessment and treatment of concussion; however, the integrity of baseline test data is essential if post-concussion test results are to be used in return-to-play decisions. Evidence of incomplete effort and recent admissions of “lowballing” the baseline test have given new interest to baseline test integrity. The aim of this study was to see to what extent athletes would be able to perform intentionally poorly on baseline testing without tripping test validity indicators. Participants and Methods: 75 undergraduate athletes who had completed their athletic careers were asked to re-take the ImPACT 6.0, which they had taken previously to establish neuropsychological baseline functioning, but to try to perform more poorly than they had at baseline without tripping any of the “red flags” or validity indicators. Results: The participants’ true baseline data were compared to their experimental baseline data. Eight participants (11%) were able to successfully fake lower scores without detection by the ImPACT’s five validity indicators and four “red flags.” “Successful” fakers were compared to unsuccessful fakers both quantitatively and qualitatively. The Reaction Time Composite and the Three Letters Total Letters Correct were the only variables on which the successful fakers chose not to perform significantly more poorly, suggesting their lack of effectiveness in detecting a “lowballer.” Concussion history was not related to performance. Conclusions: The successful fakers tended to use more mild faking strategies which naturally facilitated errors than did the unsuccessful fakers. The data suggest that “lowballing” the baseline, even under conditions involving motivation, instruction, and experience with the test, is difficult to accomplish without being detected.