So one of my favorite mid-season activities is going back over the results and figuring out how the teams performed week-in, week-out to see who has used up their best performances and who has gotten their truly awful games out of the way. It’s interesting to see who is improving/regressing but more so, this fits into a broader assumption that over the course of a season a team will have performances that roughly fit a normal distribution. This is commonly referred to as the 10–3–3 theory: over 16 games, in 3 games a team will significantly over-perform, 3 games they will significantly under-perform and 10 games they come in near their expectation.
Couple quick notes on how these were calculated:
Using the Football Outsiders offensive and defensive DVOA for each team through the first half of the season, matched up offense with defense to calc expected performance percentile for each game played. Using a distribution of points scored over the last eight seasons, inferred expected points scored and expected points conceded based on expected performance percentile. Using the same distribution, pulled the percentile that each team actually performed to and calculated the difference in standard deviations between expected points and actual points.
For example in the first game KC@NE: we know the Chiefs offense is 20% better than average, we know the Pats defense is 21% worse than average, combining these we expected the Chiefs would score at the 90th percentile which is 35 points, they actually scored 42 which is 0.6 standard deviations better than expected. Similarly the Chiefs defense is 11% worse than average, the Pats offense is 25% better than average and they get a bump for playing at home so we would also expect Pats to perform at the 90th percentile which is 35 points, they actually scored 27 which is 0.7 standard deviations worse than expected. Summing the Chiefs and the Pats we get Chiefs 1.3 total and Pats -1.3, so Chiefs have used up one of their beauties while Pats have gotten a stinker out of the way.
Here are all the results with a few brief observations…
Dallas came out of their bye hot but crashed back to earth at ATL … would expect the Giants to have some better performance ahead… we have yet to see Philly lay an egg… Washington zig-zagging a bit but not seeing extreme highs and lows.
Falcs trending in the right direction of late, surprised we haven’t seen a truly horrendous performance from them… Panthers showing an ability to bounce back from their lows… Saints on a 7-game heater after two stinkers to start the season… the Bucs are bad and performing as expected week-in, week-out.
Bears erratic early and stable as of late… Lions under-performing against good teams and over-performing against bad teams… GB tough to expect a great performance from them now without ARodg… Amazing that the Vikes are in the conversation and we still haven’t seen their best yet!
Cardinals have done well out of their bye but trouble likely ahead… Rams now three games in a row where they’ve performed well above their expectations so FOA probably needs to update their numbers… Still haven’t seen a true stinker from the Seahawks so look out… Niners finally win but still haven’t see them truly exceed their expectations yet.
Bills really in a free fall… Fins on a downward trend over the course of the season… Pats remarkably consistent with the opening night loss their only true stinker so far… since Week 3, Jets among the most steady, predictable teams in the league, go figure.
Texans a different team without Watson… Colts surprisingly improved lately… Jags the most extreme highs and lows of any team so far with four amazing performances already in the books… Titans bottomed out at HOU week 4 and have stabilized.
Ravens have been Jekyll and Hyde so far this season… Bengals flat-lined on the wrong side of zero out of their bye… still waiting on the Browns to do something special… Steelers zig-zagged early but have settled into the season minus the post-bye blah.
Broncos good early-season followed by an atrocious mid-season with four stinkers in five weeks… Steady decline in the Chiefs performance after a hot start… Chargers have been fairly predictable with one great performance and one stinker both in division… Raiders have been under-performing for a while, interested to see what they do out of the bye.
For reference, here are the same plots through 15 weeks in 2016: