From Kode v. Carlson, 2010 U.S. App. LEXIS 3936 (9th Cir. Feb. 25, 2010):

Whether we may rule on the merits of a Rule 59 motion for a new trial based on the weight of the evidence where the district court has not yet done so because it found the motion waived appears to present an issue of first impression in this court. Assuming, without deciding, that we may rule on the merits in such circumstances, we refrain from doing so in this case for the following reasons.

Review of the merits of a Rule 59 motion for a new trial is confided to the discretion of the district court. Although the trial judge can weigh the evidence and assess the credibility of witnesses, we may not. Landes Constr. Co. v. Royal Bank of Canada, 833 F.2d 1365, 1371-72 (9th Cir. 1987); see also Allied Chemical Corp. v. Daiflon, Inc., 449 U.S. 33, 36, 101 S. Ct. 188, 66 L. Ed. 2d 193 (1980) ("The authority to grant a new trial . . . is confided almost entirely to the exercise of discretion on the part of the trial court.").

We review the trial court's decision on a Rule 59 motion for a new trial on the grounds that the verdict is against the clear weight of the evidence for an abuse of discretion. *** In many, but not all, cases where we have reviewed a denial of a Rule 59 motion for a new trial based on the clear weight of the evidence, we have reviewed for a "clear" abuse of discretion, a wording that emphasizes our deference to the jury's findings and our obligation to decide matters of law, not of fact. *** The addition of the word "clear" does not change the core review for an abuse of discretion, but rather emphasizes the limited nature of our appellate function. See Piper Aircraft Co. v. Reyno, 454 U.S. 235, 257, 102 S. Ct. 252, 70 L. Ed. 2d 419 (1981) (referring to a "clear abuse of discretion" standard before referring back to a mere "abuse of discretion" standard and examining for "reasonable" discretion); cf. La Buy v. Howes Leather Co., 352 U.S. 249, 77 S. Ct. 309, 1 L. Ed. 2d 290 (1957) (referencing a district court's exceeding or refusing to exercise its functions while discussing a clear abuse of discretion). Specifically, where the basis of a Rule 59 ruling is that the verdict is not against the weight of the evidence, the district court's denial of a Rule 59 motion is "virtually unassailable. In such cases, we reverse for a clear abuse of discretion only where there is an absolute absence of evidence to support the jury's verdict." [Citations omitted.]

*** A finding of abuse of discretion is warranted when the district court's conclusion — although not perhaps the same conclusion that we would reach — was outside of a broad range of permissible conclusions.

Assuming, without deciding, that we have the power to rule on the merits of a Rule 59 motion that the district court erroneously denied as waived, we hold that in order to rule for Kode on the as yet unaddressed merits of Kode's Rule 59 motion, we would have to determine that a district court ruling, on remand, for Carlson would necessarily involve an abuse of discretion. Conversely, to rule for Carlson, we would have to determine that a district court ruling, on remand, for Kode, would necessarily involve an abuse of discretion. We note in passing that additional considerations might apply in a case in which the jury returned a verdict of at least $1 in damages, because we also review for abuse of discretion a district court's decision to condition grants or denials of new trial motions on remittiturs. ***

Kode and Carlson stipulated as to negligence and some physical injury. There was substantial evidence supporting Kode's allegations of economic and non-economic harms as well as Carlson's defense to the allegations. Under the abuse of discretion standard, even if substantial evidence supports the jury's verdict, a trial court may grant a new trial if the verdict is contrary to the clear weight of the evidence.... The record does not demonstrate that it would necessarily be an abuse of discretion, or beyond the pale, for the district court to determine that the clear weight of the evidence required damages of at least one dollar, and that a new trial is required. The record also does not demonstrate that the district court would necessarily abuse its discretion by refusing to grant a new trial based on the clear weight of the evidence. In these circumstances, even if we have the power to affirm on the merits the district court's denial of the Rule 59 motion, we would instead remand for consideration of the motion's merits.