What are the grounds for a new trial in a civil case?

A trial court's authority to grant a new trial "is established and circumscribed by statute." (Oakland Raiders v. National Football League (2007) 41 Cal.4th 624, 633 (Raiders).) Under Code of Civil Procedure section 657 (section 657), the grounds for granting a new trial include excessive damages and "[i]nsufficiency of the evidence to justify the verdict." ( 657, subds. (5) & (6).) A new trial may not be granted on either of these two grounds unless the trial court is convinced based on its review of the entire record that "the court or jury clearly should have reached a different verdict or decision." ( 657, italics added.) "California courts have consistently required strict compliance with section 657." (Raiders, at p. 634.)