Chiefs by the Numbers: How the Chiefs adjusted to Mahomes’ injury

Jan 27, 2023 - 4:45 PM

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In this series, we review the Kansas City Chiefs’ performance primarily using Next Gen Stats (NGS) — along with other advanced metrics that turn up during the season. For any questions on the statistics used in this series, please refer to our Football Analytics Glossary and Metrics page.

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Now completing his fifth year as a starter, Kansas City quarterback Patrick Mahomes has now made it to five straight AFC Championship games. This time, that required gutting out a one-legged victory during last Saturday’s Divisional Round victory over the Jacksonville Jaguars.

Using NGS data, we will show that despite his high ankle sprain, Mahomes' second-half performance was one of the best of the Divisional Round.

Before the injury

Until he was hurt, we were probably seeing the beginning of an all-time Mahomes performance. He had completed 10 of 12 passes for 77 yards and a touchdown.

What was more impressive was the way he was creating plays with his legs. On his first 12 pass attempts, Mahomes was averaging 3.17 seconds to throw, per NGS. Over the season, his average was 2.89 seconds. Mahomes was averaging 8 yards of scrambling on each pass attempt before the injury, making a throw on the run on 41.7% of them. NGS also figures that he spent more than 50% of his time with the ball outside of the pocket.

Since the Jaguars play a lot of man coverage, it appeared that Kansas City intended to make the Jaguars defend its receivers long enough for Mahomes to escape the pocket and make plays down the field. Early on, the plan was working. It looked like we were going to see an explosive game from the quarterback.

After the injury

After backup quarterback Chad Henne led the Chiefs on a 98-yard touchdown drive, Mahomes returned at the beginning of the second half — and gave one of the gutsiest Chiefs performances I have ever seen. Even with a bum ankle, Mahomes kept the Kansas City offense on track with 12 completions on 18 attempts for 118 yards and a touchdown.

Even to the naked eye, it was evident that Mahomes wasn’t at 100%. Next Gen Stats paints a more specific picture. After the injury, Mahomes’ time to throw decreased from 3.17 to 2.64 seconds. Just 5.6% of his passes were made while on the run — compared to 41.7% earlier in the game — and his time spent in the pocket increased from 50% to 88.9%.

Mahomes essentially became an immobile pocket passer. Head coach Andy Reid and the offensive staff were able to craft a second-half game plan that paired well with the situation.

The Chiefs used plays that allowed receivers to get the ball quickly — and in open space. After the injury, Kansas City receivers accounted for 62.8% of the team’s passing yards after the catch. That compares to 44% before Mahomes was injured.

All in all, NGS said Mahomes’ performance was the best by any quarterback in the Divisional Round. It gave the Chiefs’ quarterback an NGS passing score of 85 and a catch rate over expectation of +6.7% — both best on the week. Mahomes finished the game with 22 receptions on 30 attempts for 195 yards and two touchdowns.

Not bad for a guy playing on one leg.

What to expect in the AFC Championship

We should expect this week’s game plan against the Cincinnati Bengals to be fairly similar to the one the Chiefs formulated on the fly against Jacksonville. The offense will likely rely on quick passes — both short and intermediate — with the occasional downfield shot. Luckily for Kansas City, its current receiving corps will work much better in this kind of scheme than those in previous years.

Specifically, the Chiefs will have to rely on JuJu Smith-Schuster and Kadarius Toney.

Per NGS, Smith-Schuster ranks fifth among wide receivers in yards after catch over expectation; 142 of his 477 yards after catch have been more than expected in the situations in which they occurred. His average air yards per catch stand at 7.3 — and his EPA of 36.6 on receptions shorter than 10 yards leads all players. On Sunday, Kansas City would be smart to get the ball to Smith-Schuster early and often.

But Toney will also be a smart choice. 64% of his receiving yards have been after the catch. His average air yards per target (0.2 yards from the line of scrimmage) make it clear that we should expect Toney to be a part of a game plan geared toward quick passing.

One other note: when he isn’t trash-talking, Cincinnati cornerback Eli Apple has a coverage EPA of 11 on quick passes, which ranks him in the bottom 10 among the league’s corners. If the plan is for a quick passing game, the Chiefs might want to target him.