Through the first seven games of the season, the San Francisco 49ers defense was infallible. Only a New England Patriots defense on pace to break DVOA records could even compare to the 49ers' success, particularly against the pass. Defensive coordinator Robert Saleh has refined his Cover-3 defense, incorporating various blitzes and wide-9 techniques up front to keep blockers guessing while the secondary clamps down on every receiving option.
The only time the 49ers allowed a positive passing DVOA performance this season was against the Cincinnati Bengals in Week 2 (subscription required), in which Andy Dalton still threw an interception. In San Francisco's worst pass defense performance of the year, they still had a DVOA against the pass of 2.1% -- essentially a net neutral.
In Week 9, the Arizona Cardinals bucked the trend. Against head coach Kliff Kingsbury, the 49ers' pass defense DVOA had a 52.4% rating, their worst mark of the year. Rookie quarterback Kyler Murray's 10.0 yards per attempt was by far the highest the 49ers have allowed this season. Murray also became the only passer this season to throw at least one touchdown (he threw two) without throwing an interception against San Francisco. Arizona's offense was both efficient and explosive against the 49ers in a way that no other team has been able to match.
True to Air Raid form, most everything the Cardinals did was common sense. It was not about concocting a perfectly convoluted route combination or looking to get tricky, but rather pinpointing fundamental weaknesses in the 49ers defense and picking on them. No single concept summarizes Arizona's success in attacking a specific coverage weakness like their two-man stick concept.
Stick concepts are an Air Raid and West Coast staple. The concept features one receiver running a 5-yard sit or out route depending on the leverage of the defender, while another receiver runs a shoot route to the flat area. The most common version of stick in the NFL right now is run out of trips with another receiver on the outside running a vertical route. You will see every team in the NFL run it that way out of trips, but it's still plenty effective as a two-man concept, and Kingsbury proved it.
This was the first time Murray completed stick against the 49ers. Arizona have a tight offset stack to the left side of the formation with a tight end (Maxx Williams, 87) and a wide receiver. Williams starts from the leading inside position in the stack, but turns immediately to the flat at the snap of the ball. The trailing outside receiver then replaces Williams and gets vertical to about 5 yards before turning to sit in the zone. Murray already knows San Francisco's boundary corner is playing off the ball in their Cover-3 scheme, so all he needs to key is where the flat defender is covering. The flat defender gets hung up on the switch between the two receivers and does not trigger to the flat on time. As a result, Williams has plenty of room toward the boundary and Murray hits him for a first down after a nice post-catch effort.
Now Arizona is running stick to the field instead of the boundary. Just like the last time, though, Murray knows that the outside cornerback in Cover-3 (Richard Sherman, 25) is not going to collapse on the shoot route. The shoot route is the responsibility of the flat defender. As the flat defender floats over to cover the shoot route in this instance, there is a wide open area of the field between Sherman and the hook defender (Fred Warner, 54). Sherman is playing too far off to close on the stick route, while Warner doesn't immediately trigger toward the stick because he appears to hesitate on the running back from the backfield. Again, Murray nails the throw for easy yards.
This works in a way that running stick out of trips may not because the coverage does not get pushed to the overloaded side of the field. Versus trips, the outside cornerback would lock onto the vertical, the flat defender would cover the shoot route, and the strong hook player would immediately slide to the stick route. There wouldn't be any ambiguities because the defense can not afford to have them when the offense is loading that many players to one side of the field. When stick works out of trips against Cover-3 looks, it does so by abusing the leverage of the hook player, not manipulating space the way two-man stick does in this instance. It's kind of a "half-dozen of one, six of another" distinction, but it's still an interesting detail that Kingsbury chose to attack.
Kingsbury added some wrinkles to the concept, too. Whether it was moving around the players, using different combinations of skill players, or running it to the boundary versus the field, no two stick concepts in this game looked exactly the same. The most interesting twist Kingsbury put on the concept in this game was to come out in a formation they had run the concept from before, motion someone out of it, then run the concept with the running back on a shoot route.
Before the motion, Arizona is in a near-identical formation here as they were in the previous example. It looks a little different because the strength is to the boundary instead of the field and the tight end is closer to the formation instead of in a wide receiver stance, but the general formation is the same. Murray motions the trailing player in the stack from the boundary to the field, creating a tight bunch to the field. Wide receiver Larry Fitzgerald (11), now alone to the right side, runs a stick route while the running back shoots out of the backfield to the flat. The play-side flat defender fans out to cover the back, leaving Murray just enough of a window to hit Fitzgerald between two defenders. Murray flashed a bit of blind confidence to throw this without much of a post-snap look, but knowing how the coverage is supposed to work versus this concept, Murray made the right choice to trust his preparation and throw the ball inside of the flat defender.
Kingsbury's successful play calling stretches beyond just finding the right concepts to beat particular coverages. Kingsbury, a confident playcaller, showed that he had no reservations about turning to certain concepts on back-to-back plays even if they did not work the first time. That may sound like Kingsbury just slamming his head into a wall and hoping to crack it eventually, but if a coach legitimately believes they have the right play cooked up, they should not necessarily shy away from it just because it failed once. Even the best play won't work every time. Smart playcallers can recognize appropriate times to dress up a concept differently and run it back after a failed attempt.
The general framework Kingsbury is working with here is a 10-yard out to the weak side and two vertical stems from the strong side, one of which is bending to the middle of the field. On this incompletion, Kingsbury calls the 10-yard out into the boundary, a route that was a staple for the Cardinals even under Bruce Arians and Carson Palmer. Murray wants to read the middle of the field during his dropback, then turn to trigger on the 10-yard out if the middle of the field is not open. The timing is such that Murray gets rid of the ball just as the out route is breaking to the sideline. Murray's timing and placement are perfect on this throw, but Sherman makes an even better play on the ball by reading the route all the way through and closing on it. Being that a 10-yard out to the boundary is fairly standard and Sherman is a smart player, it's no surprise he could make such a fantastic play. That didn't stop Kingsbury from trying it again.
Rather than target Sherman on the boundary again, Kingsbury flips the play to attack the field. Throwing routes toward the sideline from the far hash can be low-percentage, but the daring head coach trusts his young, rocket-armed quarterback to stick the throw. Kingsbury's faith proves worthwhile as Murray drills the throw well before the defensive back can react, bailing the Cardinals out of a tough third-and-10.
There are a few reasons Kingsbury believes this should work simply by flipping the play. For one, it's probably nice for an inexperienced quarterback like Murray to be able to work the same concept back-to-back and draw from his experience the first time around to execute the second time. Additionally, Emmanuel Mosley, while impressive playing in place of an injured Ahkello Witherspoon, is not as talented or savvy as Richard Sherman. To dig in a little deeper, because a 10-yard out to the field is such a difficult throw, it's also less likely any cornerback would jump on this the way Sherman did on the boundary. Most quarterbacks can not stick the throw consistently anyway, so the risk of trying to play it aggressively does not outweigh safety in cheating toward vertical or middle-of-the-field routes. Murray's arm talent isn't like most quarterbacks, though, and concepts such as this find a home in Arizona's playbook because of it.
As the last clip hinted at, San Francisco has not seen a quarterback this season who can compare to Murray's arm talent. Jameis Winston and Baker Mayfield are probably the next-best arm talents among the 49ers' opposing quarterbacks this season, and both of their arms pale in comparison to Murray's. Murray not only has a better arm in terms of raw power, but the ease and quickness at which Murray can summon that strength from any platform is only outclassed by elites such as Patrick Mahomes and Aaron Rodgers.
What permeates throughout all of Murray's film is how well he follows through on his throwing motion regardless of platform. Murray, like Mahomes or Rodgers, can take shortcuts or unique avenues to get to his throwing platform, but once he's there, he will never make a mistake in drawing power from where he needs to and following it all the way through his throwing motion. His malleable mechanics can be in part attributed to his days as a baseball player, of which more quarterbacks than you may realize can also say the same. The looser, thrown-on-the-run nature of baseball forces players to learn different mechanics than what is taught as standard in football, and the best quarterbacks find ways to incorporate those baseball mechanics into football.
Murray also has the raw arm talent to hit throws that no other quarterback has been able to against the 49ers. Mahomes, Rodgers, healthy Cam Newton, and Russell Wilson are the only other quarterbacks in the league with the pinpoint placement and face-melting velocity to stick a deep crosser into a nonexistent window. A few other guys may be talented enough to stumble into a completion like this from time to time, but Murray is in an elite tier of arm talent in which you can say a throw of this difficulty is not beyond his limits.
The path to success is still long and winding for Murray. Half a season, much less a single game, is not nearly enough to crown the young Cardinals passer as the second coming. Murray will be pressured, challenged, and battered to hell over the next couple of seasons before we will have a full grasp on who he is as a player. That being said, not many quarterbacks over the past few years can say they stuck it to a historically good pass defense at the midway point in their rookie season.
Murray's growth through just nine games in Kingsbury's offense is as impressive as anyone could have hoped for, especially after Josh Rosen's stagnation last season. The Air Raid experiment has been a success to this point and pumped a refreshing sense of optimism back into the Cardinals organization. On behalf of anyone wishing for football to be as fun as possible, hopefully Murray and Kingsbury are only scratching the surface of what they are capable of together.