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Super Bowl LVIII features a buffet of juicy storylines. Patrick Mahomes looks to enhance his legacy. Brock Purdy can cap off one of the greatest underdog stories in NFL history. Andy Reid vs. Kyle Shanahan is a matchup of coaching geniuses. You might also hear a thing or two about Taylor Swift. 

But, for me, the most fascinating storyline on the field is the chess match between 49ers head coach Kyle Shanahan and Chiefs defensive coordinator Steve Spagnuolo, particularly with Spagnuolo's blitz.

The 49ers are the best team in the NFL against the blitz. It starts with Shanahan, an offensive mastermind armed with the best supporting cast in the league and a QB in Purdy who hits his playmakers on time and with precision. San Francisco led the NFL in yards per play when blitzed (8.7) and Purdy led the NFL in yards per pass (10.5) in those situations.

The Chiefs defense ranked top five in both blitz rate (37 percent) and yards per play allowed when blitzing this season (5.9). Spagnuolo can throw the kitchen sink at opposing QBs, and he did this season, sending a defensive back blitzer on the third-most plays (108) in the league. 

It all adds up to the best strength vs. strength battle in the Super Bowl between two incredible coaches armed with the best talent in the game. 

Passing vs. blitz this season


Brock PurdyChiefs Defense

Comp pct

70%

56%

Yards per attempt

10.5

5.9

Pass TD-INT

15-2

11-3

Passer rating

133.2

85.3

Spagnuolo has been lauded for teaching a masterclass on blitzing in the Chiefs' 17-10 AFC championship game in Baltimore vs. the presumptive MVP in Lamar Jackson. The Chiefs blitzed 20 times in that game. All 20 were different blitzes in terms of who blitzed, from where and with what coverage. Let that sink in. Twenty blitzes. All different.

The aggressive and unpredictable nature of Spagnuolo's blitzes led to Lamar Jackson's worst performance of the season. The Ravens scored 10 points, tied for their fewest this season, and Jackson had his worst completion rate of the year, plus more turnovers (two) than touchdowns (one). 

Jackson was 8 of 18 passing vs. the blitz, including 1 of 6 when the Chiefs sent at least six pass rushers. Kansas City sent a defensive back blitzer a season-high 12 times, with Jackson going 3 for 10 for 21 yards on those plays.

It's not just Spagnuolo's design. His talented defense can make plays even when the offensive line has everyone accounted for, like defensive back Justin Reid did here.

The coverage on the backside also plays into the Chiefs' outstanding attack. The Chiefs only had five in coverage here, but still blanketed Baltimore as the play got blown up in the backfield.

Adding to the unpredictable nature of the Chiefs' extra pressure is how often Spagnuolo will dial it up. The Chiefs blitzed the Ravens 44 percent of the time, their highest rate in a game since Week 13 at the Packers. But, they didn't blitz over 25 percent of the time in playoff wins vs. the Dolphins and Bills. If Super Bowl LIV is any indication, though, San Francisco can expect extra rushers. Spags' unit blitzed Jimmy Garoppolo nearly half the time in that game, their second-highest rate of the 2019 season. 

No doubt Shanahan's group will be ready with answers to the Chiefs' blitz and they are better equipped at QB to handle them this time around. One answer is pre-snap motion. The 49ers ran motion at the second-highest rate in the NFL this year. It creates confusion on defense and could alert the QB to what type of coverage he is facing. If Purdy already has answers to the test before the snap, good luck! He averaged an absurd 11.0 yards per pass attempt with pre-snap motion vs. the blitz this season. While he didn't do much right in a loss to the Ravens, he did find George Kittle for this long catch-and-run. It was preceded by two 49ers going in motion before the play with defenders following across the line, letting him know he was likely facing man coverage.

The 49ers' second answer is screen plays. If Shanahan can catch a Chiefs blitz with a well-timed screen his team could find paydirt in a hurry. Purdy led the NFL in yards per pass attempt on screens (8.8) this year (Purdy haters already know this), and it was even better when it was a screen vs. the blitz (9.7). 

The most aggressive defense the 49ers faced this season was the Vikings, headed by defensive coordinator Brian Flores. They sent extra rushers on half of Purdy's attempts, but their cover zero blitz got burned here vs. the 49ers' swing pass to Christian McCaffrey with blockers out in front. And yes, nobody's wide receivers block downfield quite like San Francisco's.

Deebo Samuel also showed the dangers of blitzing San Francisco when he took this screen pass to the house for a dagger in Philadelphia. 

The 49ers' third answer for the blitz is play action, which can employ a designed rollout to evade pressure or freeze the pass rush as a fake is used. Purdy ranked fourth in yards per attempt vs. the blitz when using play action this year.

Purdy vs. blitz this season

PurdyYards Per AttemptNFL Rank

Overall

10.5

1st

With pre-snap motion

11.0

1st

With screen

9.7

1st

With play action

10.2

4th

The common thread that makes the 49ers offense the most efficient in the NFL, especially vs. the blitz? YAC. 

The 49ers led the NFL in yards after catch per reception for an NFL-record sixth straight season this year. San Francisco averaged 8.2 yards after catch per reception when the defense blitzed this year, versus 5.7 when they did not. Simply put, when the 49ers athletes get out in space with fewer players in coverage it adds up to more big plays. 

With any game, Super Bowl LVIII could swing on a turnover and Purdy has been do or die vs. pressure at times. However, he only has two turnovers against the blitz this season. One on a batted pass vs. the Ravens and another vs. the Vikings after he was reportedly concussed on an earlier play. 

So yes, the 49ers have the head coach, QB and personnel to answer Spags' vaunted blitz. I'd still give the Chiefs blitz the upper hand. This is the second-best defense Purdy has faced this season, behind the Ravens, who Purdy threw four interceptions against. The Chiefs blitz won't be giving him the same look very often, and they will disguise their coverages well, making for the most difficult blitz San Francisco has faced all year.

It's been said pressure busts pipes or creates diamonds, so it's fitting that the Chiefs blitz could be the deciding factor to determine if Kyle Shanahan, Brock Purdy and Co. get their first ring. 

Super Bowl LVIII goes down Feb. 11 on CBS. The game will also be broadcast on Nickelodeon and streamed on Paramount+.