Analytics Recap: Kansas City Chiefs Lose to Los Angeles Chargers 38-21

What do the advanced metrics have to say about the Kansas City Chiefs' 38-21 loss to the Los Angeles Chargers?
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The Kansas City Chiefs finished the 2020 regular season with a 14-2 record after losing to the Los Angeles Chargers, 38-21. The Chiefs rested nearly all of their starters in this game, including all of their offensive starters. On the other hand, the Chargers played star quarterback Justin Herbert for the full game, in which he racked up three passing touchdowns and a rushing touchdown. This was Herbert's third 4+ touchdown game of the season and he finished his rookie season with 36 total touchdowns, giving him one of the best starts to a career in NFL history.

The Chiefs will get next week off, as the playoffs kick off and the AFC's No. 2-7 seeds battle to join the Chiefs in the AFC Divisional Round on January 16-17. The Chiefs' potential opponents in the Divisional Round are the No. 4-seed Tennessee Titans, No. 5-seed Baltimore Ravens, No. 6-seed Cleveland Browns and No. 7-seed Indianapolis Colts.

Here are the advanced numbers from the Chiefs' loss to the Chargers from Ben Baldwin's

EPA = Expected Points Added, SR = Success Rate, 1st% = First Down Rate

EPA = Expected Points Added, SR = Success Rate, 1st% = First Down Rate

Both passing offenses were really good in this game, with the Chargers having a 0.64 EPA per dropback and 0.71 EPA per early-down dropback and the Chiefs having a 0.35 EPA per dropback and an EPA per late-down dropback well over 0.70. On the other hand, the Chiefs' run game was really off in this one, having -0.27 EPA per run and a 41% success rate on those runs. 

Chiefs 2020 W17 Chargers Players EPA

The Chiefs had a few especially effective receivers in this game, with Darwin Thompson earning 6.5 EPA over eight targets, Demarcus Robinson getting 4.1 EPA and an 86% success rate over seven targets, Byron Pringle getting 5.1 EPA and 67% success rate over six targets and Mecole Hardman getting 2.4 EPA and two first downs in his two targets. Unfortunately, the Chargers' weapons were better, having six players with 3.0 or more EPA with Mike Williams' 13.0 EPA, Justin Jackson's 7.5 EPA, Stephen Anderson's 5.0 EPA, Donald Parham's 3.9 EPA, Austin Ekeler's 3.4 EPA and Tyron Johnson's 3.2 EPA. 

CPOE = Completion Percentage Over Expectation (Completion Percentage minus Expected Completion Percentage), QBR = ESPN's Quarterback Rating metric

CPOE = Completion Percentage Over Expectation (Completion Percentage minus Expected Completion Percentage), QBR = ESPN's Quarterback Rating metric

Justin Herbert was sensational in this game. 23.0 EPA, 0.57 per play, a 6.6 CPOE and an 87.3 QBR over 40 plays. I believe he is truly a star quarterback and will be the Chiefs' greatest threat to winning the AFC West every year for many years to come. Meanwhile, Chad Henne did very well here in his first start in six years with 11.6 EPA, 3.8 CPOE and a 66.7 QBR over his 38 plays. To do this with all Chiefs' backups against the Chargers' starting defense is quite impressive and you have to hope that, in case the worst-case scenario happens, Henne can take over and do an adequate job when needed.

Chiefs 2020 W17 Chargers Biggest Plays

The two biggest plays of the game went in the Chargers' favor with Mecole Hardman's muffed punt in the second quarter being worth 5.0 EPA and the second-biggest play was a 48-yard touchdown pass from Justin Herbert to Mike Williams worth 4.9 EPA. Of the next five meaningful plays, four were in the Chiefs' favor with a Chad Henne 37-yard pass to Darwin Thompson on 3rd & 9 that was worth 3.7 EPA, a Henne 31-yard pass to Byron Pringle on 3rd & 8 that was worth 3.3 EPA, the Chiefs defense stuffing Herbert on 4th & goal at the 2 that was worth -2.9 EPA and a Henne eight-yard touchdown pass to Thompson that was worth 2.9 EPA.

Chiefs 2020 W17 Chargers Win Probability

Thanks to all of the players that the Chiefs rested in this game, the Chargers had the win probability for the entirety of Sunday's game. They began the game with a 74.3% win probability and the Chiefs actually had a couple of strong surges early in the game to get their win probability as high as 48.4% around three minutes into the second quarter. The Chargers finished the half strongly though, getting their win probability up to 92.0% at halftime. The Chiefs got their win probability up to 13.0% with 4:30 left in the third quarter, but it was short-lived, as it got back to below 10% shortly after and then for the rest of the game.

NFL Team Tiers 2020 Week 17 10-90 WP

The Chiefs have finished as the second-best team in Offensive EPA per play, trailing only the Green Bay Packers. For the regular season, there are three teams who were clearly above the rest with the Chiefs, Packers and Buffalo Bills all finishing as the top three offensive teams and none finishing in the bottom-10 defensively. This is what keeps the Tennessee Titans from being the fourth-best team in the NFL, as a bottom-five defense for EPA per play. Instead, the Tampa Bay Buccaneers, Cleveland Browns and Baltimore Ravens all seem to be in a better position to succeed. 

Chiefs 2020 W17 Early Down Pass Rate Chart

After finally taking the top spot in early-down passing rate last week, the Chiefs fell below the Houston Texans on the final day of the regular season. The Chiefs finished the regular season with a 62.8% early-down passing rate, while the Texans finished with a 63.0% rate. Trailing them were the Buffalo Bills with a 62.3% rate, Pittsburgh Steelers with a 61.5% rate and Seattle Seahawks with a 61.5% rate. After those five, no one else had an early-down passing rate over 57.5%. 

Chiefs 2020 W17 Only Early Down Pass Rate Chart

For just Week 17, the Chiefs were third in early-down passing rate, trailing the Texans and Bills. For early downs with a 20-80% win probability when excluding the final two minutes of each half, the Chiefs had a 71.4% rate, the Texans had a 74.2% rate and the Bills had a 72.0% rate. These high passing rates served the Chiefs and Texans especially well, as the Chiefs had 0.287 EPA per early-down dropback and the Texans had 0.312 EPA per early-down dropback.

NFL QB Chart 2020 Week 17 10-90 WP

Finally, we have quarterback rankings by EPA and CPOE. Based on these two metrics, Aaron Rodgers was certainly the best quarterback in the NFL this season with a 0.457 EPA per play, a 6.7 CPOE and a 0.240 EPA+CPOE composite score. Following Rodgers are Patrick Mahomes and Josh Allen, who were quite even in these metrics. Mahomes finished with a 0.347 EPA per play, 3.2 CPOE and a 0.189 EPA+CPOE composite score, while Allen finished with a 0.312 EPA per play, 6.2 CPOE and a 0.194 EPA+CPOE composite score. Coming in fourth was Ryan Tannehill with a 0.180 EPA+CPOE composite score and the fifth-highest was Tom Brady with a 0.179 EPA+CPOE composite score.

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