Statistically, Kyler Murray had an excellent game on Thursday against the San Francisco 49ers. He threw for 241 yards and two touchdowns, with a completion percentage of 70.83%. Those numbers look even more impressive when you consider that Murray produced those statistics against an elite 49ers defense. However, most of that production was not the result of exceptional play by the rookie quarterback. According to his Week 9 PFN Offensive Share Metric (OSM) grade, Murray struggled immensely. The metric calculates how responsible a player was for their own production, and Murray received the meager grade of 7.83. In other words, although his statistics were impressive, Murray’s play was not the primary factor involved in his success.
Murray’s intended and completed air yards
Many factors go into calculating a quarterback’s OSM grade. In Murray’s case, two of the most influential in his Week 9 PFN OSM struggles were intended air yards (IAY) and completed air yards (CAY). IAY measures how far past the line of scrimmage a pass traveled in the air before being caught or falling incomplete. Passes that do not reach the line of scrimmage count as negative yards in the calculation. CAY is very similar but only looks at passes that were actually completed. These metrics are useful because they allow us to isolate the portion of a pass that the quarterback had direct control over.
Against the 49ers, Murray’s IAY and CAY were both remarkably low. On average, his passes traveled a mere 3.9 yards past the line of scrimmage across his 24 attempts and 2.3 yards across his 17 completions. Both of these averages were the lowest of the week (this article was written before Monday night’s game). These statistics imply that Murray barely pushed the ball downfield at all and that his receivers were responsible for a majority of his yardage. In fact, when you extrapolate Murray’s CAY across those 17 completions, his air yards accounted for just 39.1 of his 241 total passing yards. The remaining 202 yards, or around 84%, were gained by his receivers after the catch.
Of course, these statistics are averages, so not all of Murray’s attempts were that short. His two touchdown passes were notable exceptions, and, because passes caught behind the line of scrimmage count as negative yards, his average is brought down by many of the screens that he threw. However, even with this context in mind, his average IAY was still incredibly low.
Murray’s lack of aggressiveness in Week 9
A natural consequence of throwing that many short passes is that Murray also rarely needed to throw the ball into contested windows, making him one of the least aggressive quarterbacks in Week 9. Just 4.2% of his pass attempts were thrown when a defender was within a yard of his target. That amounts to just one of his 24 passes. Many of the passes that Murray threw were designed to get the ball to his receiver in open space, so that low percentage is at least in part a byproduct of how Arizona was running their offense. However, as I already mentioned, not all of his completions were on screens. And this statistic shows that even on the passes he did throw further downfield, his receivers were still not tightly covered.
There is one more advanced metric that is particularly relevant to why Murray struggled according to the PFN OSM in Week 9: expected completion percentage. On every pass attempt, the NFL calculates how likely it is to be completed based on numerous factors, from how much pressure the quarterback was under, to how open the wide receiver was. Murray’s 70.8% completion percentage looks impressive on paper. However, his expected completion percentage was 6.2 yards higher than that, at 77%. That differential was one of the worst of the week so far. So, despite how easy the passes Murray attempted were on paper, he still completed significantly fewer of them than he arguably should have. This statistic in particular reflects poorly on Murray and the Arizona offense. Despite primarily attempting what should have been low-risk passes, they failed to convert them significantly more often than they should have.
Kyler Murray’s Week 9 PFN OSM struggles were not entirely his fault
Looking at all of these statistics combined, it rapidly becomes clear why Murray’s OSM grade was so low. He did not attempt to do very much as a passer, and what he did do was less effective than it should have been. On the whole, his wide receivers and running backs contributed far more to the passing offense than he did. That’s not to imply that Murray played terribly. He certainly made some impressive plays on Thursday. Both of his touchdown passes showed how talented he truly is. He also made some plays with his legs, which the OSM does not take into account. Overall though, his impact on his own production and on Arizona’s offense as a whole was relatively minimal.
That said, Murray is not entirely to blame for his lack of effectiveness. Head coach Kliff Kingsbury clearly had a plan for this game. The quick, low-risk passes help to take pressure off of his inexperienced quarterback and neutralize San Fransisco’s pass rush. So, in many ways, Murray was doing exactly what his coach asked him to, if not much more. And to Kingsbury’s credit, the strategy worked. The Cardinals scored more points against the 49ers defense than any other team this season. But it would be a mistake to heap praise upon their young quarterback for that success. Kyler Murray’s Week 9 PFN OSM struggles almost certainly hindered their ability to win this game, even if not much was asked of him. Hopefully, in the future, Kingsbury will open up the offense a little more, and we can see what Murray is really capable of.