USC and Iowa play different styles of football.

The Trojans are powered by their star-studded offense. This season, offensive coordinator Graham Harrell revitalized the Trojans’ passing game with his air-raid philosophy. The new scheme benefited true freshman quarterback Kedon Slovis, who took over the role after an ACL injury to sophomore JT Daniels in Week 1.

Slovis, who passed for over 3,200 yards on the season in only nine full games, emerged as one of the top freshman quarterbacks in the nation. His top three receivers — senior Michael Pittman Jr., sophomore Amon-Ra St. Brown and junior Tyler Vaughns — combined for nearly 3,000 yards.

USC’s running backs failed to make a big impact on the team this season. The Trojans had four players rush for more than 300 yards, but no Trojan back rushed for more than 500 yards. Injuries plagued the team early, forcing USC to find talent deep on its roster.

One surprise in USC’s run game came from the emergence of Markese Stepp — the freshman consistently broke tackles and gave the Trojan faithful hope that USC’s historical ground-and-pound offense had reemerged. However, Stepp will not play in the Holiday Bowl following his ankle surgery in late October.

USC will need its stars to continue to shine and make an individual effort to beat Iowa. In contrast, Iowa relies on team football to beat its opponents.

USC has not played against a team with Iowa’s defensive capabilities this season. The Hawkeyes defensive line is led by junior A.J. Epenesa, who led the team with 9 sacks this season.

Iowa’s defense has not given up more than 24 points in a game this season. In comparison, USC has scored 24 or more points in 11 of its 12 games. Iowa is able to control its games by maintaining control of possession — the Hawkeyes average nearly 32 minutes of possession per game.

The Hawkeyes’ defensive backs have limited opponents to only 2,210 passing yards and 12 receiving touchdowns on the season. Senior Michael Ojemudia led the team with three interceptions.

On offense, Iowa is led by senior quarterback Nate Stanley, who has 2,738 yards on the season. Stanley throws a lot of safe passes; he has only thrown for multiple interceptions in a game once this season and twice in his career.

Iowa’s offensive prowess comes from the depth of its running backs. Similar to USC, Iowa uses a committee-style system at running back. Freshman Tyler Goodson can change direction quickly and is adept at breaking tackles; he is coming off of a 116-yard performance against Nebraska. Junior Mekhi Sargent is Iowa’s power back; he pushes the pile for consistent first downs.

Unlike the Trojans, the Hawkeyes don’t have many star receivers — this season, junior Ihmir Smith-Marsette led the team in both yards and touchdowns with 676 yards and 4 touchdowns.

One of USC’s keys to the game will be limiting penalties. The Trojans have lacked discipline this season, resulting in 71.33 penalty yards per game — the 7th-worst average for a Division I team. USC likely won’t be able to capitalize much on Iowa penalties, as the Hawkeyes concede just 33.17 penalty yards to their opponents each game.

Although the air-raid strategy has made USC’s offense more productive this season, the Trojans will need to incorporate some balance against a tough Iowa secondary. The Trojans’ biggest loss this season came against Oregon when they relied too heavily on the air-raid scheme, with Slovis passing 57 times. Now that junior Stephen Carr and redshirt junior Vavae Malepaei are healthy, the Trojans will need to incorporate the run to avoid forcing passes and giving up picks.

USC’s offense will also need to score early in order to force Iowa to abandon its ground-and-pound game and put the ball in the air. Iowa averages a less-than-stellar 230.25 passing yards per game; its passing game shouldn’t pose much of a threat to a healthy USC defensive backfield.

For Iowa to be successful defensively, it will have to pressure the Trojans to force passes and turn the ball over.

To counter the Trojans’ productive offense, the Hawkeyes will look to punish on the ground with a versatile running game that averages 139.5 yards per game. Goodson, Sargent and Young must consistently exploit the holes and break tackles in order to find the end zone against USC.

Finally, the outcome of the game could come down to coaching. Iowa has been successful using the Kirk Ferentz style of play-calling: taking advantage of all three downs, only calling passing plays when there is an opening and gashing opponents with the punishing blow when they least expect it. Along with play-calling, it will be important for the head coaches to instill discipline, something which USC head coach Clay Helton has come under fire for this season.

Iowa will be honoring former head coach and College Football Hall of Fame member Hayden Fry, who passed away on Dec. 17, by removing its helmet decals. Fry coached at Iowa from 1979-1997 and won three Big Ten Championships during his tenure. The game will kick off at 5:00 p.m. on Dec. 27 and will be nationally televised on Fox Sports 1.