Labor & Employment Law Daily Wrap Up, NAA CORNER—An arbitrator’s perspective on effective post-hearing briefs, (Dec 18, 2025)

By Charlene MacMillan, NAA Member

The arbitration process is designed to provide parties with full opportunities to present their cases to a neutral, and obtain due consideration of their respective positions before a decision is made. This extends even beyond the evidentiary hearing, during which each party to the matter has the chance to present their cases in the manner they deem most advantageous. Thereafter, the process usually provides one final chance for the parties to make their case to the arbitrator, in the form of closing briefs.

Post-hearing briefs give parties an opportunity to make their final arguments in light of the full scope of the dispute as it stands at that time. In the wake of the hearing, advocates generally have a clearer understanding of the opposing party’s positions and defenses, and may be guided by this knowledge in crafting their closing arguments. Indeed, a party’s own positions may have shifted to some degree in the course of the arbitration, and new or altered considerations may be accounted for in closing arguments. This comprehensive perspective, along with a few overarching considerations, is valuable when preparing closing briefs.

Strong Closing Briefs Highlight What Matters Most

Perhaps the most frequent disappointment experienced by those who present cases at arbitration is finding that the arbitrator did not address some argument they presented. Most frustrating, of course, are those times when the argument an advocate viewed as most important is inadequately treated, or not addressed at all.

The closing brief should leave the arbitrator in no doubt about a party’s main argument or most important position. A useful way to approach the brief might be to start with this question: If you were allowed to tell the arbitrator only one thing, or to make only one argument in closing, what would it be? In the course of the hearing, you may have been presented with a number of rabbits to chase, potentially persuasive arguments made by the other party you feel must be responded to. But it is critical to ensure, first and foremost, that the brief conveys to the arbitrator not only what matters most, but why. A full discussion of the most important aspects of the case, from the perspective of the advocate and her stakeholders is essential.

Make the most important argument and facts the first thing you discuss and, to the extent you can, let that set the tone for the rest of the brief. Look for opportunities to weave it into other arguments and issues you address in the brief; contrast it with other positions and ideas, and show how and why it’s superior to other considerations.

Strong Closing Briefs are Focused

A very long brief is sometimes appropriate, and even necessary, but sheer length is unlikely to persuade the arbitrator of the merits of your case. A more focused brief that says up front what you most need the arbitrator to understand and remember, and which carries that theme throughout, is more impactful than a lengthy brief with immaterial, unhelpful, or repetitive statements that do not reflect what you most need to communicate.

While it will inevitably add volume, an irrelevant or unsupported argument is not similarly guaranteed to increase the persuasiveness of the brief. In the most unfortunate situations, it can signal a potential weakness in the case that the arbitrator can’t unsee. And though it is important to address arguments and defenses raised by the other party during the hearing, the greater benefit lies in responding to those who have the potential to undermine your own positions. Be strategic when selecting your final arguments.

Be mindful that a closing brief that differs significantly from positions pursued at hearing may have the effect of communicating that you have amended your pleadings. Arguments excluded in this final step of the arbitration will be deemed abandoned, a signal to the arbitrator that it does not need to be answered in the Decision. Consider whether your brief unintentionally signals a change in pleadings.

Arguments crafted to demonstrate how the evidence supports your position are generally more effective than those that seek to guide the arbitrator’s analysis of the case. It is generally not necessary to educate the arbitrator on any of the fundamentals of collective bargaining or arbitration. The arbitrator is familiar with the rules of contract interpretation and will be able to determine, based on the record and the nature of the dispute, which should apply. Similarly dispensable is recitation of the 7 tests of just cause, even when presented for purposes of convincing the arbitrator that a party has checked, or has failed to check, the requisite boxes. Most arbitrators do not apply this well-known method when deciding a case, but will base their analysis on the totality of the record and the specific evidence that demonstrates whether just cause existed.

If you feel it necessary to elucidate some principle of contract interpretation or arbitral standard in your brief, be careful not to bury any of your important points within that commentary. Doing so will increase the likelihood that important aspects of your closing argument will be missed. If you must address the basics, make certain your main points will stand out.

Strong Closing Briefs are Persuasive

Arguments backed by solid evidence are powerful. Taking the time to highlight the evidence that supports your arguments will give the arbitrator a greater appreciation for the position you have taken. Discuss any and all evidence on the record that proves the merits of your case, and address those that may have the opposite effect; it’s better to include a thoughtful response to such evidence than to ignore those facts and risk having potentially damaging issues stand as the established record. When appropriate, explain why certain evidence should be given more or less weight, what context should be brought to bear, and whether you believe any of it should be disregarded.

Citing to other arbitration decisions can be an effective means of bolstering your own finely tuned arguments, but be careful how you choose. Avoid selecting a decision based on keywords, or on a rudimentary skimming of the headnotes. In so doing, many an advocate has encouraged their arbitrator to consider cases that were irrelevant at best or, at worst, particularly helpful to the opposing side. The arbitrator will take note of variances in fact pattern, context, and other factors that may affect their cogency.

Ultimately, the purpose of the closing brief is to persuade the arbitrator of the merits of your position. The brief helps to highlight the most significant interests, positions, and arguments that remain after the grievance procedure has progressed through all of its stages. It’s important to be intentional about what should be included in the brief, and take the time to show how the evidence supports the position taken. A well-crafted and focused closing brief can help to ensure all aspects of the case deemed important by the parties will be addressed, and may even convince the arbitrator of the merits of the case.

About the author. Charlene MacMillan has served as advisor, advocate, and chief negotiator in the private and public sectors and is skilled in interpretation, negotiation, and administration of collective bargaining agreements. In addition to being an NAA member, she serves on several national and regional arbitration panels, and holds permanent panel appointments in the federal, public, and private sectors.

Companies: National Academy of Arbitrators

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