5 Super Bowl storylines to watch as Chiefs, Eagles vie for NFL supremacy

Super Bowl LVII kicks off Sunday at 6:30 p.m. ET in Glendale, Arizona. These focal players and key battlegrounds will help decide whether the Chiefs or the Eagles lift the Lombardi Trophy.

Patrick Mahomes' moment

Kansas City's inimitable star quarterback just won his second NFL MVP trophy. He passed for the most touchdowns and threatened Peyton Manning's single-season yardage record despite no longer getting to throw bombs to Tyreek Hill, his longtime No. 1 receiver. The NFL's average passer rating is 89.1, per Pro Football Reference; Mahomes' rating hasn't dipped below 105.0 in a game in two months.

He's easily the best player Philadelphia will face this season. Mahomes leads all quarterbacks in expected points added per play, postseason included, by a vast margin, according to Ben Baldwin's database.

The Eagles only played four playoff teams in the regular season, stoking claims that the defense had an easy ride. That said, they faced three quarterbacks who rank in the top 10 in EPA/play - Dak Prescott, Jared Goff, and Trevor Lawrence - and went up against seven QBs who appear in the top 20.

In eight matchups - Daniel Jones was a repeat opponent - those seven QBs averaged 200.1 passing yards, posted a 63.2% completion rate, and combined to throw 10 touchdowns and eight interceptions. The Eagles went 6-2 in those games, only losing when Jalen Hurts was injured late in the year.

Philadelphia's defense is menacing. Four pass-rushers - Haason Reddick, Javon Hargrave, Brandon Graham, and Josh Sweat - cleared double digits in sacks in the regular season and amassed 49 sacks as a quartet, which was more than 28 entire teams managed. The Eagles ranked No. 1 in DVOA against the pass, per Football Outsiders. They defended the fourth-most passes in the league and finished fifth in interceptions and total takeaways.

Only two teams surrendered fewer sacks than Kansas City, while Mahomes posted the league's best passer rating on dropbacks where he was kept clean, according to PFF. He won't be fazed if the Chiefs trail Sunday. They top the NFL in offensive EPA/play in the second half of games, when most offenses tail off and Philly's offense slips to 15th in effectiveness, per Baldwin's data.

These Eagles can run

Rushing the ball is Philly's offensive strength. The Eagles ran for 32 touchdowns in the regular season, the most any club has racked up since 1976, per Stathead. Hurts opened the postseason by passing for two scores against the Giants, then teamed with Miles Sanders and Boston Scott to punch in the Eagles' last seven TDs on the ground.

Their backfield is stacked. Sanders picked up 1,269 yards as the lead back this season, Hurts became the second QB ever to rush for 700 yards and 13 TDs, and Kenneth Gainwell set career highs in carries and yardage in the first two playoff games. Scott has scored in three straight outings, charging to pay dirt behind the sport's best offensive line.

The Eagles regularly rush for huge yardage. They burned the Packers for 363 yards in Week 12, accumulated 253 yards against the Giants in Week 14, and ran for 268 yards to thump New York in the divisional round, becoming the 12th team this century to exceed 250 yards three times. Dialing up runs on close to two-thirds of the offensive plays helped Nick Sirianni's squad keep possession for more than 35 minutes against the Giants and 49ers.

The Chiefs allowed a mere 10 rushing TDs this season. They ranked 15th in DVOA against the run as tracked by Football Outsiders, meaning they probably won't roll over like the 32nd-ranked Giants did. But it's hard to know which Eagle will get the ball on any given snap and hard to stop such a shifty, powerful corps of carriers.

Off-board MVP candidates

Quarterbacks have won 31 Super Bowl MVP awards. They've won six of the past 10 and 13 of the 22 handed out this century. It's probable that Mahomes or Hurts will be laureled in Glendale.

Five wideouts and four defensive players have been named MVP since the turn of the millennium.

Punctuating a productive day with the decisive catch strengthens a receiver's MVP candidacy. Defenders have to stuff the stat sheet in a dominant team performance. Ray Lewis, Malcolm Smith, and Von Miller's respective squads allowed no more than 10 points when they won the Super Bowl.

Who could upstage the winning passer this year? Here are four contenders.

Travis Kelce: The Chiefs tight end set career highs in targets, receptions, and touchdown catches this season and moved into fifth at his position in career approximate value, surpassing Rob Gronkowski, per Stathead. No tight end has been the MVP before, but Kelce holds the positional record for receiving yardage in a Super Bowl (133 on 10 catches against the Buccaneers two years ago).

Chris Jones: The Chiefs defensive tackle tees off on quarterbacks like an Eagle. Jones put up four multi-sack games in the regular season, the most among interior linemen, then hauled down Joe Burrow twice in the AFC Championship Game when he recorded his best PFF defensive grade (92.3) in a playoff contest.

DeVonta Smith: The Eagles receiver, who ranked ninth among wideouts in catches, heated up late in the season. Smith grabbed four touchdowns in December and eclipsed 100 receiving yards four times in a five-game span. A.J. Brown is the greater big-play threat, but the Giants and 49ers quieted him in their playoff clashes, while Smith scored on a screen pass against New York.

Haason Reddick: The Eagles edge rusher forced an NFL-high sixth fumble of the year when he knocked Brock Purdy out of the NFC title game. If Reddick's pressure causes Mahomes to throw errantly, safety C.J. Gardner-Johnson - the league interception co-leader - is a candidate to come up with a big takeaway.

The fourth-down battle

Both teams convert their fourth-down attempts at elite rates despite approaching the situation differently. Philadelphia is aggressive on fourth down, while Kansas City is selective.

The Eagles lead the league in fourth-down conversions because of Hurts' versatility. Seven of his 11 pass attempts on fourth down moved the chains this season. Three were explosive completions to Smith that resulted in 41-yard, 34-yard, and 29-yard gains.

Opponents have to respect the pass while dreading the run. Hurts sneaked or scrambled past the chains on 14 of his 15 fourth-down rushing attempts. Famously able to squat 600 pounds, Hurts also benefits from teammates legally pushing and pulling him the required distance, as The Athletic's Kalyn Kahler detailed recently. Sirianni has trusted him to gain a yard plunging up the gut from as deep as Philadelphia's own 30-yard-line.

Andy Reid's conservatism sometimes holds Kansas City back. He went for it on fourth down when that was his best option this season less frequently than every team except the Saints, per Baldwin's data. This decision didn't ultimately haunt the Chiefs, but punting in Bengals territory with the score tied decreased their win probability late in the AFC title game.

To be fair to Reid, Tommy Townsend led the NFL in net punting average, meaning he tends to flip the field in Kansas City's favor. True to form, he pinned the Bengals at their 6-yard line on the punt in question.

The Chiefs ranked first in scoring despite Reid's cautiousness, and they usually capitalized when he opted to be bold. Townsend botched a fake field goal in September, but the Chiefs scored three touchdowns on fourth down throughout the year, finding the end zone just as often as they failed to prolong the drive.

Meet the kickers

The 38th Super Bowl was the last edition to be won on a buzzer-beating kick. But 12 Super Bowls this century have been decided by one possession. Either kicker could nail timely field goals to keep the score close or cost his team dearly by channeling Brett Maher.

Philadelphia's Jake Elliott was reliable this season. He led the NFL with 51 made extra points on 53 attempts. He's connected on 10 straight field goals since pinging the upright on a 38-yarder in Week 15, Elliott's first miss inside 40 yards in two years. He's never missed a field goal in the playoffs, converting 13 in nine career appearances.

Harrison Butker's 75% hit rate on field goals ranked 30th this season and was a significant career low. That said, he only missed twice from inside 50 yards, his accuracy improved from mid-November onward, and he walked off the Bengals from 45 yards out to send the Chiefs to Glendale. Promisingly, Butker went 4-for-4 on field goals over Kansas City's last two Super Bowl trips.

Nick Faris is a features writer at theScore.