Andy Reid's risk aversion could cost him the Super Bowl

Andy Reid and the Kansas City Chiefs are bringing into the Super Bowl one of the greatest offenses to ever line up on an NFL field. In fact, the Chiefs’ passing attack with Patrick Mahomes has had the greatest two-year stretch of efficiency in the PFF era (2007-2019). In this playoffs, the Chiefs’ offense hasn’t looked to slow down, and Mahomes is laying a strong claim to the greatest quarterback postseason we’ve seen. The San Francisco 49ers, and their No. 1 defense according to our Massey rankings, may be the best equipped in the NFL to stop the Chiefs’ offense, though our understanding of the more predictive nature of offenses and defenses don’t point to that outcome.

After digging into the numbers for the Chiefs’ offense the last two seasons, specifically in games they went on to lose, you see the possibility an enemy closer to home might hold back the Chiefs, and one entirely under their control. The Chiefs have exceeded baseline expectations strongly in all game conditions, except when they have big leads. You find more evidence that the issue could be systemic when focusing directly on play-calling choices and fourth-down decisions, which shows a strong tendency for conservatism, at least relative to how they play when the game is close or they’re behind.

This apparent conservatism playing from ahead looks more pronounced against high-scoring opponents, the exact kind you should approach with more aggression. If Reid wants to finally capture his first championship, he can help his chances by embracing the wide-open, pass-happy offense he tailored for the Chiefs personnel, even when far ahead.

Chiefs become an average team with a big lead

The plot below shows a smoothed line incorporating all the offense plays for the Chiefs in games Mahomes finished from 2018 to 2019. It contrasts the expected win probability based on historical league averages for each game-state (score differential, time remaining, down, distance, etc.) to actual wins and losses. The dotted line represents a team winning exactly as often you’d expect in every game-state, above the line more often, and below the line less often.