Week 4 in the Pac-12: What to watch for

Here are five things to keep an eye on this week in the Pac-12:

Chase for the crazy South begins: The Pac-12 South has been one of the more difficult divisions to project in all of college football. In the past four seasons, the division has seen four different winners: UCLA (2012), Arizona State (2013), Arizona (2014) and USC (last season). The first critical game in the division race is on Friday night, when USC travels to Salt Lake City to face Utah.

The Utes are hoping to be the fifth champion in as many seasons. They are one of just two undefeated teams left in the South (ASU is the other) and one of four in the conference (Stanford and Washington). These teams had matching conference records last year, both going 6-3. But the Trojans won the head-to-head game in Los Angeles, giving them the chance to play in the conference title game.

USC will debut a new quarterback this week. Head coach Clay Helton announced Monday that Sam Darnold would get the start over Max Browne. Through three games, Browne had completed 63.2 percent of his throws (55 of 87) with two touchdowns and two interceptions. Darnold, in spot duty, was 14 of 22 (63.6 percent) with two touchdowns and one interception. He makes his start against a Utah defense that is allowing 12 points per game and is second nationally with 15 sacks.

NoCal vs. SoCal: Stanford began its title defense last week with a convincing 27-10 win over USC -- a rematch of last year's Pac-12 title game (also dominated by the Cardinal). This week Stanford will look to sweep the LA schools when the Cardinal travel to Pasadena to face UCLA. The Bruins will do their best to slow down Christian McCaffrey, who has at least 200 all-purpose yards in eight consecutive games.

Stanford has been the tree in UCLA's ointment for some time. The Bruins have dropped eight straight to the Cardinal. Per ESPN's Stats & Information, it's their longest losing streak against a single opponent since joining what is now the Pac-12 in 1928. Five of those losses have come under Jim Mora's watch.

Defense optional? California and Arizona State have had almost mirror seasons so far. And when the Bears make the trip to the desert, expect lots and lots of points.

ASU is second in the conference, averaging 48 points per game. Cal is right behind with an average of 47 points per game. That's good for the Bears. But they also are last in the league in scoring defense (39.7 points per game). And ASU is 11th (32 ppg). So that's bad for them.

Arizona State has set two conference records in consecutive weeks. Against Texas Tech two weeks ago, running back Kalen Ballage accounted for a record eight touchdowns. And then, last week against UTSA, kicker Zane Gonzalez broke the Pac-12 career scoring record, which now sits at 424. With 81 career field goals, he's seven shy of matching the NCAA record (88 by Florida State's Dustin Hopkins).

Both have scored major wins (with major scoring) against Big 12 teams. The Sun Devils topped Texas Tech 68-55 in Week 2 and Cal survived No. 11 Texas last week at home, 50-43.

Hype check: So far the Washington Huskies have lived up to their billing. They check in at No. 9 this week in the AP poll, climbing from preseason No. 14 on the strength of three impressive victories over teams that, frankly, they should have had impressive wins against. But now that they’ve wrapped up nonconference play, we'll see just how worthy the Huskies are of all their preseason accolades.

Washington kicks off its Pac-12 schedule with a trip to Arizona. The home team has won the past eight meetings and is 5-3 at home against ranked teams. Last year in Seattle, the Huskies walked away with a 49-3 laugher, with Jake Browning throwing four touchdowns and running for another.

After this week, Washington hosts Stanford and then travels to Oregon in a pair of games that will likely shake out the pecking order in the North.

Battle of the M.A.S.H. units: With the exception of Boise State's trip to Oregon State, the rest of the slate is all conference play. Washington State is the only team on bye, and after Friday night’s USC-Utah game, the rest of the games are North vs. South.

Colorado limps into Oregon with some key injuries. The Buffaloes have already lost kicker Diego Gonzalez and linebacker Derek McCartney for the season, and quarterback Sefo Liufau is day-to-day with an ankle sprain.

The Ducks have had similar bad luck. Receiver Devon Allen and left tackle Tyrell Crosby are both out of the year and running back Royce Freeman is day-to-day.