Sunday, October 9, 2016

NFL Playoff Implications - Week 5

Here are playoff implications for week five of the NFL season. The purpose of this feature is to highlight games that have a significant impact on the playoff picture (see this post for background).

The playoff implications below are derived from a 50,000 round simulation of the remainder of the NFL season. I use my daily NFL rankings to simulate future games. I can group the simulation runs by the outcome of each game and then see how a team's playoff chances vary between the two groups. The interactive table at the bottom of the post will allow you to see corresponding results for any game or team. The results of the Thursday night game have already been taken into account.

Ranking Week 5 Games by Leverage

The table below ranks the week 3 games by total leverage. Leverage in this context is a measure of both how uncertain a game's outcome is (games between evenly matched teams have higher leverage) and how much the playoff picture swings as a result of that outcome.

Wednesday, October 5, 2016

NFL Week Four Power Ranking Roundup

10/7/2016 update: The original version of this post had the incorrect FPI rankings. The table has now been updated and some of the text as well. Thanks to Steve in the comments for pointing out the error.

For the past several years, I have archived various NFL power rankings following week four of the season. When the regular season is finished, I compare how accurate each ranking was at predicting wins for weeks 5 through 17. Over the past nine seasons, the most accurate ranking system was the Vegas-based ranking system I publish here on my site.

Here are the rankings:


  • SRS - What's known as the Simple Ranking System, which is based solely on margin of victory and strength of schedule.
  • DVOA - Football Outsiders' DVOA rankings, a proprietary ranking system based on analysis of detailed play by play data.
  • 538 - FiveThirtyEight's Elo rankings. The Elo ranking system was originally developed for chess, but has been extended to the NFL by Nate Silver.
  • ESPN - ESPN's weekly NFL power rankings.
  • Market - The betting market rankings found here at inpredictable.
  • FPI - ESPN's Football Power Index (stat-based model developed by Brian Burke).

  • In addition to these rankings, the table below has two additional columns:
    • Consensus: The consensus ranking derived by taking a straight average of each team's ranking.
    • Consistency: How consistently a team is ranked by the various systems.
    Here is the ranking table:

    team SRS DVOA 538 ESPN MARKET FPIConsensusConsistency
    DEN 4 4 1 1 5 1 1 5
    MIN 3 3 3 5 4 2 2 2
    PIT 2 5 4 3 3 4 3 3
    SEA 10 2 2 2 2 7 4 14
    PHI 1 1 9 7 9 6 5 17
    GB 8 6 6 6 6 3 6 4
    NE 12 17 5 4 1 5 7 30
    ATL 5 8 13 8 12 11 8 9
    CIN 11 12 10 10 10 12 9 1
    CAR 9 21 8 15 8 9 10 28
    BUF 6 10 11 20 16 10 11 26
    ARZ 15 16 12 17 7 8 12 21
    DAL 7 9 17 11 17 14 12 20
    OAK 13 7 21 9 14 13 14 25
    KC 19 15 7 18 11 15 15 24
    BAL 14 11 16 14 19 21 16 15
    NYG 16 20 22 12 20 20 17 16
    SD 18 13 24 22 21 16 18 19
    HOU 29 29 14 13 13 18 19 32
    WAS 20 14 20 19 22 24 20 13
    LA 25 24 15 16 23 29 21 29
    NYJ 27 32 18 21 15 22 22 31
    NO 22 18 26 24 28 19 23 18
    IND 30 27 23 26 18 17 24 27
    DET 21 26 19 25 24 28 25 12
    MIA 17 22 25 30 26 23 25 22
    JAC 31 19 30 23 27 26 27 23
    CHI 26 23 28 28 29 27 28 6
    TEN 28 25 32 27 31 25 29 8
    SF 23 28 27 31 30 31 30 10
    TB 32 30 29 29 25 30 31 7
    CLE 24 31 31 32 32 32 32 11

    The consensus #1 team is the Denver Broncos. The team ranked most consistently is the Cincinnati Bengals, with a ranking that varies from just #10 to #12. The least consistently rated team is the Houston Texans. ESPN and the market have them ranked 13th, while DVOA and SRS have them at #29.

    Overall, the rankings with the least disagreement are my market rankings and FiveThirtyEight's Elo rankings (Spearman correlation of 94%). The two rankings with the most disagreement are Football Outsiders' DVOA and the market rankings (Spearman correlation of 66%).

    Check back at the end of the regular season for the results.