There’s a case just out of the First Circuit that shows how procedural posture can change the standard of review on appeal. Mrs. M sued the Falmouth school district for violations of the Individuals with Disabilities Education Act. The district court granted summary judgment to the school district and the First Circuit affirmed.

Then Mrs. M did something that seems fairly reasonable: she asked for permission to file an amended complaint that addressed the flaws pinpointed by the First Circuit’s decision. This is a common tactic after losing a motion to dismiss—but Mrs. M wasn’t trying to fix problems with how she stated her claim, she was trying to fix problems with the substance of her claim. That is less common. The district court denied Mrs. M’s motion and she appealed.

What’s interesting is that the district court denied the motion in a way that changed the standard of review on appeal. Usually a court of appeals reviews a decision allowing or refusing an amended complaint for abuse of discretion. Abuse of discretion is the most forgiving standard of review. But the district court based its ruling on the law of the case, a legal rule that says an issue should only be decided once in a lawsuit. And a court of appeals reviews a decision based on law of the case without deference, the least forgiving standard.

The standard of review can make a big difference on appeal. Colter Paulson, a Cincinnati-based member of Squire Patton Boggs’ appellate group, writes on the Sixth Circuit Appellate Blog that “[a]ppellate lawyers think about arguments in terms of the applicable standard of review . . . .” And in the Sixth Circuit, “the standard of review matters”: The Sixth Circuit is likely to affirm an opinion reviewed for abuse of discretion but it reverses opinions reviewed without deference a striking 20% more often than any other standard. That short paragraph at the start of your argument is one of the most valuable parts of your appellate brief second only to the fact statement.

In Mrs. M’s case, the change in the standard didn’t help her after all: The First Circuit held that the district court was right under either standard. But it’s not hard to picture a scenario where this procedural posture changes the outcome of the case. And you’ve probably read one—any case where the appellate opinion says something to the effect that ‘we might not have done this, and we understand why the appellant is unhappy, but it’s not an abuse of discretion. Affirmed.’