The lodestar for all eDiscovery, proportionality is the principle that the burden of production must correspond to the importance of the evidence and the stakes of the case. Until December 1, proportionality was embodied in Fed. R. Civ. P. 26(b)(2)(C)(iii) (permitting a court to limit discovery where “the burden or expense of the proposed discovery outweighs its likely benefit . . .”), but now it resides in Rule 26(b)(1) (limiting the scope of discovery to matter that is relevant “and proportional to the needs of the case, considering” various factors). Predictive coding generally weighs in favor of proportionality by making it less burdensome to cull responsive from non-responsive evidence.