What we can learn from from college football's biggest Week 5 games

Week 5 of the college football regular season features no shortage of high-profile games and intriguing storylines

This Saturday is highlighted by four ranked matchups, but the undercard features a slate of games that could shake up the hierarchy entering October.

Here are five things we're most interested in learning this weekend.

How legit is LSU's defense?

The LSU defense has been a pleasant surprise after being the program's Achilles' heel in the first three seasons under head coach Brian Kelly. The unit ranks ninth in the country in scoring defense (9.3 points per game) and has been elite at stopping the run, allowing 56 rushing yards per game against FBS competition. Transfer corner Mansoor Delane has been arguably the most valuable offseason addition by any program, allowing four receptions for 36 yards on 18 targets with an interception. (h/t Pro Football Focus)

Wins over Associated Press preseason top 25 teams Clemson and Florida, which are a combined 2-6, are much less impressive in hindsight, but Saturday's road game at No. 13 Ole Miss (4-0, 2-0 in SEC) will give us a much more accurate gauge of how good No. 4 LSU (4-0, 1-0 in SEC) is on defense. 

Ole Miss quarterback Trinidad Chambliss, who transferred from Division II Ferris State during the offseason, will start for the third consecutive game. He was excellent in wins over Arkansas and Tulane, completing 67.9 percent of his pass attempts for 660 yards (11.8 yards per attempt) and adding 174 rushing yards on 29 carries with five total touchdowns. Ole Miss averaged 43 points per game.

The Tigers have struggled against mobile quarterbacks in recent years, with Texas A&M's Marcel Reed and former Alabama quarterback Jalen Milroe exposing the unit last season, and Saturday's test could be just as daunting.

Were pronouncements of Alabama's demise premature?

No. 17 Alabama (2-1) was pronounced dead by some after a surprising 31-17 Week 1 loss at No. 8 Florida State (3-0), but it can re-enter the national conversation with a win at No. 5 Georgia (3-0, 1-0 in SEC). Since that opening week loss, Alabama has defeated Louisiana-Monroe and Wisconsin by a combined score of 111-14, which should give it confidence heading into the massive late-September SEC showdown. The program is also 44-26-4 all-time against Georgia, winning nine of the past 10 meetings, including a 41-34 victory last September.

Is Penn State a national title contender?

With No. 6 Oregon (4-0, 1-0 in Big Ten) heading to Beaver Stadium, No. 3 Penn State (3-0) has a chance to change the narrative surrounding its troubling recent history. The program is 16-28 against ranked opponents under head coach James Franklin (since 2014), including just 1-17 versus top-10 teams during the regular season. Oregon is one of three FBS programs entering Week 5 with each of its first four wins coming by at least 20 points, joining No. 12 Texas Tech and No. 18 Vanderbilt.

Is USC a team to watch in the Big Ten?

No. 21 USC (4-0, 2-0 in Big Ten) has flown under the radar despite its offense being of the best in the country, averaging 52.5 points per game. The team's next three games are against ranked opponents, beginning on Saturday at No. 23 Illinois (3-1, 0-1 in Big Ten), which will determine how seriously we should take USC as a Big Ten contender. Former junior college running back Waymond Jordan has been an incredible story, leading USC with 443 rushing yards (110.8 yards per game) after transferring from Hutchinson Community College in January.

Illinois will have something to prove itself after sustaining a humbling 63-10 loss to No. 11 Indiana last Saturday, making this ranked conference game one of the weekend's most compelling matchups.

Can ranked teams handle true road tests?

Eight ranked teams go on the road for games against unranked power conference opponents, six of which have a winning record. Here's the list:

No. 1 Ohio State (3-0) at Washington (3-0)

No. 8 Florida State (3-0) at Virginia (3-1, 1-0 in ACC)

No. 11 Indiana (4-0, 1-0 in Big Ten) at Iowa (3-1, 1-0 in Big Ten)

No. 15 Tennessee (3-1, 0-1 in SEC) at Mississippi State (4-0)

No. 16 Georgia Tech (4-0, 1-0 in ACC) at Wake Forest (2-1, 0-1 in ACC)

No. 22 Notre Dame (1-2) at Arkansas (2-2)

No. 24 TCU (3-0) at Arizona State (3-1, 1-0 in Big 12)

No. 25 BYU (3-0) at Colorado (2-2, 0-1 in Big 12)

Washington might be the country's most overlooked team, receiving no votes in the latest AP poll despite outscoring its opponents 167-55 through three games.

Virginia sixth-year senior quarterback Chandler Morris, a North Texas transfer, is completing 70.8 percent of his passes for a Virginia offense that ranks 11th in the country in scoring (45.5 points per game), giving it chance to perhaps keep up with Florida State's high-octane offense.

Indiana is 10-25-3 all-time at Iowa, with its last win coming in 2007. 

Mississippi State's pass defense has been a revelation through four games, with the program ranking 14th in FBS in passing yards allowed per game (129 yards per game), making a trip to Starkville a potential stumbling block for Tennessee.

Wake Forest, Arkansas and Colorado might be easier to dispatch, but reigning Big 12 champion Arizona State is a serious threat to knock TCU from the undefeated ranks, entering Friday's game as a 3.5-point favorite.