A trial court serves as a "gatekeeper" on a motion for new trial. It opens the gate only rarely, a testament to the fact that the vast majority of trials resulting in conviction are fairly conducted. In these cases, motions for new trial are routinely made, routinely denied, and are routinely affirmed on appeal. In the remaining cases, however, the trial court grants the motion, and we affirm those rulings in the absence of a clear showing of abuse of discretion. ( People v. Sherrod, supra, 59 Cal. App. 4th at p. 1175.) As indicated, general rules pertaining to appellate review of the trial court's discretionary rulings are apposite to motions for new trial. The trial court's ruling on a motion for new trial "rests so completely within [its] discretion that its action will not be disturbed unless a manifest and unmistakable abuse of discretion clearly appears." ( People v. Delgado (1993) 5 Cal. 4th 312, 328 [19 Cal. Rptr. 2d 529, 851 P.2d 811], quoting People v. Williams (1988) 45 Cal. 3d 1268, 1318 [248 Cal. Rptr. 834, 756 P.2d 221]; see also 6 Witkin & Epstein, Cal. Criminal Law (2d ed. 1989) Appeal, 3210, pp. 3970-3971.) Although this standard of review is deferential, "it is not empty . . . . It asks in substance whether the ruling in question 'falls outside the bounds of reason' under the applicable law and the relevant facts." (People v. Williams (1998) 17 Cal. 4th 148, 162 [69 Cal. Rptr. 2d 917, 948 P.2d 429].) The appellant has the burden to demonstrate that the trial court's decision was "irrational or arbitrary," or that it was not " 'grounded in reasoned judgment and guided by legal principles and policies appropriate to the particular matter at issue.'" (People v. Superior Court (Alvarez) (1997) 14 Cal. 4th 968, 977 [60 Cal. Rptr. 2d 93, 928 P.2d 1171]; see also fn. 1, ante.) "Where the motion is made on a proper statutory ground, and the record contains some showing in support of it, the judge's discretion in granting is almost invariably upheld; i.e., the appellate court gives the order all of the presumptions in favor of any appealable judgment." (6 Witkin & Epstein, Cal. Criminal Law, supra, 3084, p. 3806.)