Morning Distribution for Thursday, December 24, 2020

A [FiveThirtyEight]( email [Morning Distribution]( Thursday, December 24, 2020 Your daily briefing from FiveThirtyEight --------------------------------------------------------------- The Morning Story [Indianapolis Colts v Tennessee Titans]( [Are Defensive Play-Callers Consistent Enough To Be Exploitable?]( By [Josh Hermsmeyer]( If NFL analytics is a set of festive Russian nesting dolls, the final pea-sized [matryoshka]( is defense. We’re actually pretty good at understanding offensive skill position players at this point. When a quarterback change is made on a team, [our models]( and the betting markets move in response. No Patrick Mahomes? “That’s bad for Kansas City’s chances! Let’s move the line down and predict fewer points scored.” But when a defender is out, everyone shrugs. No Xavien Howard? “Um, well, I’m not sure what that means for Miami.” We know so little about defense that some [unhinged analysts]( have even pounded out “defense doesn’t matter” on various social media platforms in fits of rage and frustration. It’s likely that the lack of predictive power in defensive analytics has to do with the reactive nature of defense. NFL defenses are highly interconnected, weak-link systems. What does weak link mean? It means that if just one person in the defensive chain fails, the entire unit is assigned that failure. We can measure that failure, but the fact that we can’t predict future defensive performance implies that the precise types of failures we’re measuring are unlikely to occur exactly that way again. Most NFL defenses are good enough to not repeat the same mistakes over and over — they just find new and exciting ways to fail. All of this makes apportioning blame and properly accounting for success pretty difficult. But a recent tweet from [Anthony Reinhard]( made me wonder if we can assign some of that blame reliably on coaches. Could we successfully predict how coaches will respond to game states like obvious passing or obvious running situations? After all, defensive coordinators typically call the defensive plays, and they’re just one person, not an interconnected unit. If we can predict what a coach will do, maybe we can gain a deeper understanding of how a defense is likely to react in certain situations. Yesterday I tweeted a graph showing the average number of defenders in box by offense. Today, I have defenses. [Read more]( --------------------------------------------------------------- Weekly Listen [Play]( [Which NBA Teams Might Make Things Interesting This Season?]( [FiveThirtyEight] [View in browser]( [ABC News]( [Unsubscribe]( Our mailing address: FiveThirtyEight, 47 West 66th Street, New York, NY 10023.