1 S.C.R. 381.
The reasonableness of a jury verdict focuses on the conclusion reached at trial – the verdict – and measures it against the totality of the evidence adduced at trial:
R. v. Sinclair, 2011 SCC 40 (CanLII),  3 S.C.R. 3, at paras. 69, 78, 81.
Under s. 686(1)(a)(i), the function of the court of appeal extends beyond merely finding that there was evidence adduced at trial to support a conviction, the verdict rendered by the jury. It is to determine on the evidence as a whole whether the verdict is one that a properly instructed jury, acting judicially, could reasonably have rendered:
R. v. Yebes, 1987 CanLII 17 (SCC),  2 S.C.R. 168, at p. 186; Sinclair, at para. 79.
In making this determination, the court of appeal is required to ask not only whether there is evidence in the record to support the verdict, but also whether the jury’s conclusion conflicts with the bulk of judicial experience:
R. v. Biniaris, 2000 SCC 15 (CanLII),  1 S.C.R. 381, at para. 40; R. v. W.H., 2013 SCC 22 (CanLII),  2 S.C.R. 180, at para. 28.
On review of a jury verdict for unreasonableness, the court is to treat the verdict rendered with great deference, according due weight to the jury who were ear and eyewitnesses to the evidence as it unspooled at trial:
W.H., at paras. 2, 27. See also: R. v. François, 1994 CanLII 52 (SCC),  2 S.C.R. 827, at p. 837.
The court of appeal must ask itself two questions:
i. whether the jury’s verdict is supportable on any reasonable view of the evidence; and
ii. whether proper judicial fact-finding, applied to the evidence as a whole, precludesthe conclusion reached by the jury:
W.H., at para. 2.
In a determination of whether a jury verdict survives a reasonableness analysis under s. 686(1)(a)(i), the court of appeal is entitled to take into account an appellant’s failure to testify to dispute the complainant’s evidence:
R. v. Pannu, 2015 ONCA 677, 127 O.R. (3d) 545, leave to appeal refused,  S.C.C.A. No. 478 and  S.C.C.A. No. 498, at para. 164; R. v. Corbett, 1973 CanLII 199 (SCC),  2 S.C.R. 275, at pp. 280-1.
686. (1) On the hearing of an appeal against a conviction or against a verdict that the appellant is unfit to stand trial or not criminally responsible on account of mental disorder, the court of appeal
(a) may allow the appeal where it is of the opinion that
(i) the verdict should be set aside on the ground that it is unreasonable or cannot be supported by the evidence,
(ii) the judgment of the trial court should be set aside on the ground of a wrong decision on a question of law, or
(iii) on any ground there was a miscarriage of justice.