The Chiefs' unheralded defense could be the X-factor vs. Brady, Bucs

The Kansas City Chiefs are in the Super Bowl for a second consecutive year, and their offense gets most of the credit for that success. That's what happens when a team has an otherworldly young quarterback, lots of speed and dynamism at multiple skill positions, and a forward-thinking coaching staff that frequently maximizes all of that talent.

But what about the defense? The Chiefs might seem capable of winning every game by simply outgunning their opponents, but they can, and do, get plenty of stops too. Whether they're able to put the clamps on Tom Brady and the Tampa Bay Buccaneers' multi-faceted offense could determine the outcome of Super Bowl LV.

Let's start with the basics. The Chiefs finished the regular season ranked 10th in points allowed (22.6) but were just 19th in expected points added per play and 22nd in DVOA. But it's a unit that's ebbed and flowed as the season has progressed; according to Aaron Schatz of Football Outsiders, the Chiefs ranked sixth in DVOA against the pass from Weeks 1-9 before falling to 23rd in Weeks 10-16. But in its playoff wins against the Cleveland Browns and Buffalo Bills, Kansas City had the most efficient pass defense of the league's 14 postseason participants.

Kansas City's defense is fairly good at preventing plays of 20-plus yards. According to PFF, the Chiefs ranked fifth in explosive run plays allowed and 13th in explosive pass plays allowed. PFF's Ian Hartitz wrote this week, "This is a bend-don't-break unit that might not completely shut down an opposing offense, but the group has the ability to stall drives in a hurry thanks to its ability to get after the quarterback."

Defensive tackle Chris Jones is a big reason why. Jones ranked 13th among all defenders in PFF's pass-rush productivity rate (8.4), which factors in sacks and hurries per pass-rush snap. He was also second among interior defensive linemen in pass-rush win rate (20%), an ESPN metric that calculates how often a defender beats his blocker within 2.5 seconds. As a team, the Chiefs ranked 12th in pressure rate.

Why does this matter for the Super Bowl? Brady, like most quarterbacks, doesn't like to be pressured. He only saw pressure on 24.4% of his dropbacks during the regular season, but when he did, his passer rating was 54.5, which ranked just 21st in the league. When operating out of a clean pocket, Brady's passer rating jumped all the way to 115.7, good for seventh best.

Kansas City defensive coordinator Steve Spagnuolo had the same gig for the New York Giants when he famously cooked up the game plan that beat Brady and the unbeaten, seemingly unstoppable New England Patriots in Super Bowl XLII. How he chooses to create pressure - and chooses to push the pocket, forcing the statuesque Brady to move - should indicate how successful the Chiefs' D can be.

According to For the Win's Steven Ruiz and Charles McDonald, Spagnuolo likes to blitz (36%, which ranked ninth) but also frequently has the Chiefs play with five or more defensive backs (76%), with a lot of man and match coverages. The wild card here is the versatility of safety Tyrann Mathieu, who can be deployed just about everywhere. Per PFF, Mathieu played 403 snaps as a slot corner, 363 as a box safety, and 275 as a free safety. When the Chiefs decide to blitz, Mathieu and cornerbacks L'Jarius Sneed and Charvarius Ward are likely to be among those flying toward Brady.

Pressuring Brady is easier said than done, of course. The Bucs' offensive line finished the regular season ranked third in Football Outsiders' adjusted sack rate and fifth in EPA per dropback. PFF graded four of Tampa Bay's linemen 22nd or higher at their respective positions. A player to watch up front will be right guard Aaron Stinnie, who will be making his third straight start for the injured Alex Cappa.

Kansas City's tendency to play so much nickel and dime personnel could make it vulnerable against the run. Indeed, per Schatz, the Chiefs were dead last in run defense DVOA from Weeks 1-9 and have been again during the postseason.

The Chiefs figure to score points; it's what they do when they seemingly want to. But the Bucs have Brady and a stable of weapons, so chances are they will, too. If Kansas City is going to repeat, it will likely be because of its often overshadowed defense.

Dom Cosentino is a senior features writer at theScore.