USC football: What will Alex Grinch's defense need to do to win national title?

The Trojans' defensive statistics last year were alarming, especially to end the season

USC's defense beat its offense in the Trojans spring game on Saturday, but in the series that mattered most, USC's first team defense struggled mightily. 

It took USC's starting offense just three plays to go 75 yards and score a touchdown against the Trojans starting defense to open the game. It was reminiscent of last season's struggles on that side of the ball.

After the first series, quarterback Caleb Williams didn't take another snap, so although USC's defense ultimately bounced back, none of those improved series came with the reigning Heisman winner under center.

In case you forgot, the Trojans' defensive statistics last year were alarming. USC had 156 total missed tackles last year, which ranked No. 120 nationally. The Trojans ranked No. 124 in opponents yards per play (6.53), No. 117 in opponents yards per rush attempt (4.98), No. 112 in points allowed (409) and No. 93 in points allowed per game (29.21).

Despite those numbers, USC finished 11-3 after going 4-8 the year prior. The 2023 Trojans team will be even better on paper and should challenge for a College Football Playoff spot. Momentum is definitely going in the right direction. 

But after a defensive finish like last season where USC gave up 45 points or more in three of its last four games, all eyes will be on the Trojans defense next season and rightfully so. 

The offense is national championship caliber. Will the defense be too?

The College Football Playoff began in 2014. In the nine years the format has been used to crown a champion, national title winners have allowed an average of 16.2 points per game. Only two champions — 2014 Ohio State and 2019 LSU — gave up an average of more than 20 points per game. The 2014 Ohio State team had the highest average of the nine winners at 22.0 points allowed per game. 

In the four years USC defensive coordinator Alex Grinch and head coach Lincoln Riley have worked together dating back to their time at Oklahoma, their defenses have allowed an average of 26 points per game. 

The average Pro Football Focus grade for defense of the nine national title winners is just under No. 9 nationally at 8.89. Every champion has been in the top 25 for defensive rating. Grinch and Riley have never had a top 25 graded defense from PFF.

So there are two benchmarks for the fall. 

It's also important to look at recruiting rankings when assessing defenses. In order to build a championship level defense, teams need blue chip prospects.

In a story in The Athletic, writer Andy Staples broke down how Riley has done recruiting top prospects on defense out of high school compared to college football's perennial powers.

"Since 2018 (the first year Riley signed a recruiting class as a head coach), Kirby Smart (Georgia) has signed 33 defensive players ranked among the nation’s top 100 recruits. Alabama’s Nick Saban has signed 37. Ohio State, coached by Urban Meyer and Ryan Day during that span, signed 20. How many such players has Riley signed at either Oklahoma or USC? Seven."

That's a major part of the story as well. Grinch could run the best scheme possible, but if USC doesn't have the players needed to win at the highest level, it's not going to happen. 

Here are the former top 100 recruits on USC's defense heading into the fall — four of the players were signed by former head coach Clay Helton out of high school: linebacker Raesjon Davis, linebacker Shane Lee, defensive lineman Korey Foreman, defensive lineman Anthony Lucas, defensive lineman Solomon Tuliaupupu, defensive lineman Braylan Shelby cornerback Domani Jackson, safety Zion Branch and cornerback Ceyair Wright. 

Exactly how much USC's defense improves going forward will have a lot to do with recruiting both from the high school ranks and the transfer portal. 

In terms of next season, if USC really is a national title contender, history tells us they'll need to give up an average of 22 points per game at most and finish the year with a defensive grade of 25 or better from PFF.