There are many reasons why a contractor might protest a procurement award, but only a few good ones, none of which are disagreeing with the outcome. With three quarters of bid protests denied by the Government Accountability Office, those that are successful tend to share key common traits. One of the most common of these is a flawed technical evaluation, and it is a high bar for contractors to meet. Here are a few tips to successfully proving an agency erred in its technical judgment.

For starters, the GAO’s starting position is to defer to the contracting agency. This means the battle is an uphill one when it comes to proving a flawed technical evaluation, particularly for complex technical solicitations or ones that involve human life and safety. But uphill doesn’t mean impossible; what it does mean is demonstrating an unreasonable or disparate application of the agency’s standards. Agencies are made of humans who are as likely to err as the rest of us, but identifying and building a case around their errors takes attention to detail, painstaking documentation and some good old fashioned elbow grease.

Comparing the terms of the solicitation to proposal content is a good place to focus that effort, but it is where the effort can be most demanding. If a contractor has already worked with a red team during the pre-bid phase, though, the inconsistencies should be apparent and the undertaking that much smoother. A red team will have done the comparison work before a bid is submitted, making it relatively simple to identify which evaluation terms were judged inconsistently. This effort may also uncover assessments that relied on assumptions rather than the proposal itself. Be careful not to waste time on areas of subjective judgements: The agencies have significant latitude to evaluate proposals and attempts to argue your merits will do little more than annoy the decision-makers.

Again, the key is searching for inconsistencies, and sometimes these occur within the treatment of offerors. For example, if an agency waives a technical requirement for one but not all, the GAO may sustain a protest. The GAO may also sustain a protest if an agency issues an award to an offeror that failed to meet solicitation requirements such as product specifications or place of performance. In cases like these where the agency should have amended the solicitation, contractors not only should protest, but may have a solid case to make the GAO side with them.

Another reason the GAO might uphold a protest is if an agency has taken a guarantee to meet a solicitation requirement at face value, despite countervailing evidence. Blanket offers of compliance are not adequate responses to selection criteria, especially when there may be reason to doubt compliance. Using the bid team to document and demonstrate why the awardee will not or cannot comply with the solicitation requirements may be worthwhile if there are underlying questions, but only if and when the agency had a whiff of them before making the award.

Similarly, a protest may be a valid one if the awardee failed to provide required information such as plans, supporting data or other particulars expressly required in the solicitation. Complete disregard for proposal requirements is generally solid footing for a protest, but it is much more common for bidders to provide “just enough” than nothing at all.

Each of these benchmarks for a protest are not only key to a potential protest, but also to being taken seriously by the GAO. With thousands of protests a year to sort through, not enough are founded in solid legal reasoning. Don’t invite an eye roll by picking a fight with an agency or questioning its technical judgment; embark in a protest only when the case has the merits to warrant it. This means relying on objective team members and partners to speak truth to power and ultimately help determine whether the evaluation was truly flawed.

John Chierichella is the founder of Chierichella Procurement Strategies, a consultancy helping contractors pursue and perform Federal contracts and subcontracts.