Super Bowl LIV was setting up to be another Andy Reid playoff letdown, an indication that Patrick Mahomes was mortal, and the latest in a long line of postseason disappointments for the Kansas City Chiefs, who hadn't advanced this far in 50 years.
And then it wasn't. After spotting the San Francisco 49ers a 20-10 lead with a little more than six minutes remaining, the Chiefs ended the game with three rapid-fire touchdowns to run away with a 31-20 victory. It was Kansas City's third comeback from a double-digit deficit in as many games this postseason. Reid's place as one of the NFL's greatest coaches is now secure, and there can no longer be any doubt about Mahomes' position as the NFL's brightest young superstar.
So how did the Chiefs go from nearly scuffling into the gutter to pulling off another sudden, resounding, come-from-behind victory? With 7:17 remaining in the game, Kansas City's win probability stood at just 3.9%, according to ESPN. Yet a little more than four minutes later, the Chiefs were ahead and never looked back.
What changed? Mahomes showed he could withstand a withering pass rush from the 49ers' front four, and Reid and offensive coordinator Eric Bieniemy made some perfectly timed adjustments to counter what San Francisco had been throwing at them.
The game turned on Mahomes' 44-yard completion to Tyreek Hill on third-and-15, two plays after Kansas City's win probability had dipped to its nadir. The play is called 2-3 Jet Chip Wasp and it was successfully completed during last year's AFC Championship Game against the Patriots. Let's just marvel that Mahomes threw this ball 56 yards through the air as DeForest Buckner was bearing down on him:
But it was the difference in the Chiefs' approach both before and after that big play that determined the game's outcome. Mahomes saw a ton of pressure all night from the Niners' front - on 41.2% of his dropbacks, per PFF, even though San Francisco blitzed just 13.7% of the time.
On the back end, the Niners' Cover 3 took away much of the Chiefs' ability to stretch the field - or at least Mahomes' willingness to try to attack them with deep targets. In the first half, Mahomes played it safe by relying on a lot of short, quick throws: He had just two attempts of more than 10 yards through the air and just one of more than 20. His average time to throw before halftime was just 2.54 seconds, somewhat quicker than the 2.67 seconds he had averaged during the regular season and the Chiefs' two playoff wins, according to PFF.
After halftime, Mahomes used a lot of deep dropbacks to try to set himself, even as the Niners - and defensive end Nick Bosa in particular - relentlessly came after him. The Chiefs' scheme did little to help him: There were few quick throws or screens or bang-bang passes out of bunch sets to try to neutralize San Francisco's heavy rush and blanket coverage.
By my count, Mahomes attempted 19 passes in the second half before that long completion to Hill. Just six of them were quick throws, rather than deep drops or scrambles in which he was flushed from the pocket. In the second half, before that deep ball to Hill, Mahomes was 7-for-14 for 77 yards, two interceptions, two sacks, one fumble (which he recovered himself), and three scrambles. His accuracy was shaky.
Mahomes threw a pair of incompletions on deep dropbacks immediately after the big play to Hill, including another aggressive shot to Hill in the end zone on the next play. Then came a pass interference call against Niners defensive back Tarvarius Moore on an end-zone shot to tight end Travis Kelce. That was before a quick play-action pass to Kelce for a touchdown. With 6:17 left, the Chiefs were within three points.
The Chiefs began to change their tempo on that drive, however, by going no-huddle for the first time on three of their 10 plays. They continued with this change of pace after they got the ball back a little more than a minute later. They began the drive with a quick wide-receiver screen to Hill …
… followed by two more plays without a huddle. The latter was another quick toss to Hill:
This took advantage of some of the space cornerback Richard Sherman was giving Hill at the snap near the line of scrimmage. But it was a setup. On the play after that, Mahomes went play-action and quickly got rid of the ball again, though this time it was a dime downfield to Sammy Watkins, who had been singled up against Sherman on that same side. Mahomes was able to diagnose this when he saw safety Jimmie Ward shading toward the middle of the field at the snap:
That play went for 38 yards, with 23 coming through the air. Mahomes had targeted 12.5% of his passes 20 yards or more through the air during the regular season and in his first two playoff games, according to PFF; this was just his third such attempt in the Super Bowl. It put the Chiefs on the Niners' 10-yard line.
After Mahomes scrambled for 6 yards and took a sack on what was really an option keeper for a loss of 1, he went short and quick again. But notice the way Hill motioned into the backfield and then how he and running back Damien Williams darted in different directions at the snap, crossing up the Niners' defense just enough for Williams to barely get into the end zone to give Kansas City the lead:
The Chiefs got the ball back with 1:25 remaining, all set to run the ball to salt the game away. Williams tacked on a final TD by darting 38 yards from scrimmage for the final margin. It took the Chiefs just 4:57 to race away with those 21 unanswered points.
After the big play to Hill, Mahomes was 6 for his next 8 for 61 yards and two touchdowns. Other than a kneel-down at the end of the game and the pass interference penalty against Moore, the Chiefs encountered just one more third down; they were 4-for-11 on third downs before Hill's 44-yard catch.
The 49ers' pass rush did have a tendency to wear out late in games. According to ESPN's Bill Barnwell, the Niners' defense came into the Super Bowl ranked second in Total QBR against in the first three quarters when leading by 10 points or fewer, but just 27th in the fourth quarter. In Super Bowl LIV, that pattern held up. The Chiefs were able to neutralize the Niners by holding their blocks, but also by getting off a few faster throws and running some pace-changing quicker plays to keep them off balance.
It's a credit to Reid and Bieniemy for adjusting, and it's a credit to Mahomes for not wilting despite all that earlier pressure. It's also a big reason why the Chiefs are champions at last.
Dom Cosentino is a senior features writer at theScore.