David Shaw thinks Saturday will be a battle between the two best quarterbacks in the Pac-12.

Of course the Stanford coach will back his guy, Tanner McKee — a popular player among NFL Draft experts and pro scouts. But he also had high praise for USC’s Caleb Williams. Asked what distinguishes the second-year quarterback, Shaw said he has a dual-threat ability that’s rare.

“I don’t want to be taken the wrong way in that people always talk about the athleticism of the Black quarterback, but the combination of his athleticism and his arm strength, it’s rare,” Shaw said. “He can run away from you, he can run over you, but he can also stay in the pocket and make the big-time NFL throws. For me, it’s that combination of his athletic ability and his decision-making. There’s really not much that he’s unable to do.

“I’ll go one further and say I don’t know that these aren’t the top two quarterbacks in our conference going head to head this Saturday in Stanford Stadium. I think as pure passers they’re both exceptional. As a runner, Tanner is under-appreciated but at the same time Caleb is special there. You’re talking about two guys that, when you watch them play, you see two NFL quarterbacks. I think it’s going to be fun to watch.”

As Stanford goes about preparing for the matchup, USC provides the double-whammy of difficulty. The Cardinal beat the Trojans last season, but that tape is pretty useless, Shaw said. The schemes in all three phases of the game are obviously different, but normally that would dictate Shaw and his staff look at personnel to try and carry some things over. They can’t do that; USC’s personnel was overhauled as well.

“Last year’s film is not going to help us,” he said.

Shaw praised Lincoln Riley’s offensive scheme, saying he does a nice job of matching his aerial explosiveness with efficiency in the run game.

USC scored 66 points in its opener. Stanford, led by 308 yards and two scores from McKee, put up 41 points in its opener. Saturday’s game — a 4:30 p.m. PT kick on ABC — should have plenty of scoring.