It's time to take another look at the top-performing Pac-12 quarterbacks. We'll revisit this ranking each Tuesday. Expect some variation here with each edition, as we'll be judging every individual game performance more heavily than the full season of work:

1. Sam Darnold, USC: Look who's leading the nation in QBR. It's not Lousville's Lamar Jackson. It's not Washington's Jake Browning. It's Darnold (91.3 QBR), a guy who began the season as the backup at USC. The redshirt freshman tossed five touchdowns in the Trojans' 48-14 rout of Arizona. He also rushed six times for 54 yards, continuing to display the versatility that has helped USC turn its season around. Darnold will now enjoy a bye week before California -- another team with a struggling defense -- comes to town, so expect another solid performance from him.

2. Sefo Liufau, Colorado: The Buffs have at least two very capable quarterbacks -- a stunning luxury considering that the talent cupboard was virtually bare in Boulder, Colorado, just a few years ago. Steven Montez did a good job filling in recently, but Liufau returned from his ankle injury in this past Saturday's 40-16 win over Arizona State. Colorado's dominant win was more about its rushing attack -- Phillip Lindsay amassed 219 yards -- but Liufau completed 74 percent of his passes while maintaining proficiency with his legs. This next test at Stanford should be fun to watch.

3. Luke Falk, Washington State: The Cougars' 27-21 win over UCLA in wet conditions wasn't pretty, but Falk's performance was enough to net the third spot on this list in what was a sub-par week for Pac-12 quarterbacks. In throwing for 261 yards, Falk surpassed the 2,000-yard mark on the season. He currently ranks seventh nationally in that category.

4. Mike Fafaul, UCLA: With Josh Rosen hurt, Fafaul stepped in to make his first career start. The rainy conditions in Pullman, Washington, weren't hospitable for this debut, and the 24-7 deficit that the Bruins faced in the fourth quarter was also anything but ideal. But Fafaul showed some moxie down the stretch, throwing a pair of touchdowns to bring UCLA to within a possession. His final line included 258 passing yards and three touchdowns. The Bruins' biggest issue remained their inability to establish a running game: They finished with only 43 yards on the ground.

5. Ryan Burns, Stanford: The fact that a quarterback from the Cardinal's ugly offensive win at Notre Dame makes this list is a testament to the slim pickings here this week. But Burns is indeed the No. 5 guy following Stanford's 17-10 win. For the fourth straight game, the Cardinal scored only one offensive touchdown. This time, though, the run-blocking was good enough to spring Bryce Love to a 129-yard performance. That allowed Burns to face a more manageable pass rush, and he did a solid job on third down as a result: Stanford converted 7-of-12 opportunities. But the Cardinal attack still has much work to do.