Proportionality is the Rule 26(b)(1) limit on discovery: material must be relevant and proportional to the needs of the case, weighed against the amount in controversy, the parties' resources, the importance of the issues, and whether the likely benefit justifies the burden. Relevance alone no longer makes something discoverable.
What the 2015 amendment changed
Proportionality factors had existed for years, buried in a subsection courts rarely reached. Moving them into the definition of the scope of discovery made them an element of discoverability rather than a basis for a protective order — which shifted who has to argue what.
It did not, as sometimes claimed, place the burden on the requesting party to establish proportionality before anything is produced. The Advisory Committee said explicitly that the amendment does not put the burden of proving proportionality on the party seeking discovery. In practice both sides carry something: the requesting party explains why the material matters, and the responding party must substantiate a burden objection with specifics rather than adjectives.
Boilerplate objections do not work
The most consistent lesson from the case law is procedural rather than substantive. An objection asserting that a request is "overly broad, unduly burdensome and not proportional" without particulars is routinely overruled, and increasingly draws a comment from the court about the practice itself.
What succeeds is quantified: the number of custodians and the volume implicated, the vendor's estimate for processing and hosting, the projected review hours and cost, and — the part most often missing — what the requesting party would actually gain. A burden figure with no accompanying assessment of likely yield invites the response that the cost is simply the cost of the case.
The factor that gets least attention
"Whether the burden or expense of the proposed discovery outweighs its likely benefit" is the operative question, and likely benefit is estimable. Sampling is the tool: run the request against a defined subset, measure the responsive rate, and extrapolate. A sample showing a 0.4% hit rate across two hundred thousand documents is a far stronger argument than any characterisation of burden, because it converts the dispute from rhetoric into arithmetic.
This cuts both ways, which is what makes it credible. A sample showing a high responsive rate ends the objection.
Asymmetry is a real factor, not a rhetorical one
The Rules list the parties' relative access to relevant information. In matters where one side holds nearly all the data — employment, consumer, product liability — that factor legitimately favours broader discovery, and a burden argument premised on volume alone tends to fail. Conversely, a well-resourced party demanding extensive discovery from a small one in a modest dispute is where proportionality does its most useful work.
Where it is actually decided
Proportionality disputes are resolved better in a conference than in motion practice, and better in an ESI protocol than in a conference. Most of what parties fight about — custodian count, date range, search terms, treatment of legacy systems — is exactly what a protocol settles at the start, at a fraction of the cost of resolving it after a production has already been attempted.
From our work
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