Sandbagging: The Dirty Secret Undermining Every Concussion Baseline Program

Sandbagging is the practice of deliberately performing poorly on a baseline concussion test so that if you later sustain a concussion, your post-injury scores will still look “normal” by comparison. It’s widespread, it’s dangerous, and it’s the elephant in every baseline testing room.

What the research actually shows

Research published in Applied Neuropsychology: Child (Bailey et al., 2021) suggests that sandbagging on baseline tests is common among high school athletes. A study conducted at Butler University found that only about 50% of intentional sandbaggers are detected by ImPACT’s embedded validity indicators — despite ImPACT Applications claiming an 89% detection rate. The Washington Post reported in 2018 that University of Wyoming researchers demonstrated athletes could be coached to successfully sandbag in under five minutes, with many evading the test’s built-in safeguards.

Why they do it

The motivation is straightforward: they want to play. If a concussion baseline shows low scores across the board, then when a real concussion drops their performance further, the decline might not look statistically significant against the artificially depressed baseline. The athlete “passes” their post-injury test and returns to play while still impaired.

This is, to put it plainly, one of the most dangerous behaviors in youth sports. An athlete who games their baseline has removed the safety net that baseline testing provides. If they sustain a concussion and are cleared based on a falsified baseline, they are at risk for prolonged recovery, second impact syndrome, and cumulative brain damage.

What can be done

First, testing environment matters. Athletes are less likely to sandbag in a supervised, one-on-one setting with a trained administrator who can observe effort and engagement than in a group testing environment where no one is watching closely.

Second, multi-domain testing makes sandbagging much harder. An athlete might be able to deliberately slow their clicking speed on a computer test, but intentionally failing a balance test or VOMS assessment without being obvious to a trained observer is significantly more difficult.

Third, education changes culture. Research by Erdal (2012) in the Clinical Journal of Sport Medicine found that athletes who receive targeted education about the purpose and importance of baseline testing are more likely to give honest effort.

How we approach it

At Headquarters, we use multi-domain baseline protocols with built-in validity checks across cognitive, balance, and vestibular-ocular testing. We administer baselines in supervised settings with trained professionals who actively monitor effort. And we educate athletes directly about why honest effort on their baseline protects them — not keeps them off the field. For a deeper look at how invalid baselines fail clinically, read why your child’s baseline test might be invalid.

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