How Patrick Mahomes’ interception helped set up a big second-half play

In a battle of two of the NFL’s elite units, the Kansas City Chiefs’ offense and the San Francisco 49ers’ defense squared off throughout Kansas City’s 44-23 win on Sunday afternoon. The first round of the game went to the 49ers.

On the third snap of the Chiefs’ opening possession, quarterback Patrick Mahomes attempted to convert a third down with a pass over the middle to rookie wide receiver Skyy Moore. But San Francisco safety Tashaun Gipson Sr. broke on the pass, blowing it up at the catch point and giving an interception to Talanoa Hufanga.

Taking a closer look at the play, we see that it’s a high-low concept that the Chiefs frequently run. With linebacker Fred Warner’s attention on the underneath route, Moore’s deeper crossing pattern has space — but Moore drifts too far upfield, giving Gipson less ground to cover as drives to the ball.

“That’s a great learning experience for Skyy,” head coach Andy Reid told media members after the game. “Skyy has a wrap-around route right there... You have to work into that spot — and you have to know how to do it. He got a little too high.

“Patrick trusted him; that was the positive part. So next time around, we’ll knock that thing out. They talked through it, so that was a good thing — a good learning experience.”

This setback on the opening drive was nearly the only one Mahomes and the offense would face all day. On the next seven possessions, Kansas City scored six touchdowns. The only drive that failed was right before halftime, when a touchdown was taken off the board after a low-block penalty was called on running back Jerick McKinnon.

Moore’s route was one of the only significant errors among Chiefs receivers, who succeeded against the man-coverage looks the 49ers were using.

“I thought our guys did a good job with it today,” Reid said about the team’s success against San Francisco’s coverage. “We had some pretty positive snaps against it — in particular at big times; we were really good on third down. That’s normally when we have been seeing it.”

The Chiefs converted six of their nine third-down attempts — but none were as important as one near the beginning of the fourth quarter. The offense needed 11 yards to convert on third down. Without it, Kansas City would have been punting back to the 49ers with only a five-point advantage.

As we see here, it isn’t man coverage. But wide receiver Marquez Valdes-Scantling still uses his long speed to burn past cornerback Charvarius Ward in quarter-zone coverage — finding space behind San Francisco’s coverage shell to gain 57 yards.

So instead of punting to the 49ers, the Chiefs set up a touchdown that gave them another two-score lead. Mahomes said that his first-quarter interception aided him in hitting Valdes-Scantling deep on the play.

“The way their safeties were playing in their Cover 4,” he explained after the game, “I knew they were going to drive JuJu [Smith-Schuster] — who was the primary on the other side. Once I saw Mecole [Hardman] clear out the middle, MVS was one-on-one — and I just put it out there.”

If you take a closer look, you can see that Mahomes sort of plays it safe with the velocity and lead of his throw.

“It was funny,” recalled Mahomes. “I told him, ‘I missed you in Indy’ — so I threw these two kind of short.”

Photo by Ezra Shaw/Getty Images

His readiness for the play (and his awareness to throw the ball with a higher chance of completion) all stemmed from Mahomes anticipating that safeties would be driving on his underneath throws.

“How they were playing, you saw it on the first pick: their safeties were driving down,” Mahomes emphasized. “They have aggressive safeties; they are really good... Once earlier in the game I saw that, we talked about it on the sideline... I said, ‘They’re in that Cover 4 shell again. If that safety drives, just make sure you keep it going down the field.’

“That’s stuff you build throughout a season — and we’re going to continue to get better and better at that.”

As the team enters the bye week, the picture of the team’s wide receiver group is as clear as ever — at least at the top. Valdes-Scantling’s 111 yards on three receptions represented the kind of big-play efficiency the Chiefs have hoped to see from him. Meanwhile, his deep patterns opened up a more voluminous underneath role for JuJu Smith-Schuster, who racked up 124 yards on Sunday.

Unfortunately for Moore, his chances for production in San Francisco ended when his lone target turned into an interception — but Reid is confident he will learn from it. Even better, Mahomes’ lesson from one of the game’s few offensive mistakes later created a game-changing opportunity.