2015 - Team Ratings After Round 13

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First up this week, a correction. Last week's ChiPS Ratings for Geelong and Melbourne were slightly in error because I neglected to input the scores for their game into the relevant Official ChiPS Spreadsheet. As a consequence, the Ratings shown were for a drawn Cats v Dees game rather than for a Dees win by 24 points. The net result of inputting the missing data was to knock another couple of Rating Points (RPs) off the Cats' Rating and to add that same number to the Dees'.

That deduction for the Cats, which dropped their Rating below 1,000 for the fourth time this season, nudged them into 10th place at the end of Round 12, though this week they regained 9th spot on ChiPS thanks to a small RP deduction for the Crows after their unexpectedly small victory over the Lions. Geelong now has the same Ranking as it had at the start of the season but with a Rating more than 8 RP lower, such is the current concentration of talent at the top end of the ladder where four teams have ChiPS Ratings of 1,022 or higher.

(As the table below retreats rapidly into illegibility in its on-screen form, a reminder that it, as all charts and diagrams on MoS, can be seen in expanded glory by the simple act of clicking on it.)

That swapping of the Cats and the Crows was the only activity on ChiPS this week. MARS, though, re-Ranked eight teams, most notably Richmond, which it lifted two places into 6th after its solid win over the higher-Rated Swans, and Adelaide, which it dropped by two places into 8th in a reaction similar to ChiPS' to the Crows' lacklustre performance over the much-lower Rated Lions.

The full set of MARS moves aligned the top 4 teams under both Systems (now, in order, Hawthorn, West Coast, Sydney and Fremantle) and left just two teams Ranked more than two places differently by ChiPS and MARS:

  • The Kangaroos (Ranked 6th on ChiPS and 10th on MARS)
  • Essendon (8th and 12th)

The correlation between ChiPS and MARS Team Ratings now stands at +0.955 and between ChiPS and MARS Team Rankings at +0.946.

Colley, Massey and ODM

Massey and ODM re-Ranked six teams this week and Colley seven, but none of those moves by any of these Systems was of more than two Ranking places.

Relative to the competition ladder now, the largest differences are for:

  • Adelaide: Ranked 10th by ChiPS and Colley but sitting 7th on the ladder
  • Essendon: Ranked 8th by ChiPS but sitting 13th on the ladder
  • Fremantle: Ranked 4th by ChiPS and MARS but sitting 1st on the ladder
  • Geelong: Ranked 7th by MARS but sitting 10th on the ladder
  • GWS: Ranked 12th by Massey and ODM, 13th by ChiPS and MARS but sitting 9th on the ladder
  • Hawthorn: Ranked 1st by ChiPS, MARS, Massey and ODM but sitting 4th on the ladder
  • The Kangaroos: Ranked 6th by ChiPS and 8th by Colley, Massey and ODM but sitting 11th on the ladder
  • Port Adelaide: Ranked 9th by MARS but sitting 12th on the ladder
  • The Western Bulldogs: Ranked 11th by MARS, 12th by ChiPS but sitting 8th on the ladder

Massey and ODM now Rank all 18 teams identically and so have the maximum possible rank correlation of +1, while ChiPS and Colley, and MARS and Colley, Rank a number of teams quite differently so their respective rank correlations are only +0.886. That said, the Rating Systems are collectively agreeing more and more about team Rankings, the rank correlation between every pair of them increasing between the end of Rounds 12 and 13.

ODM Offensive and Defensive Rankings

According to ODM, the Top 5 teams in terms of Defense are now:

  1. Fremantle (no change)
  2. Sydney (no change)
  3. West Coast (up from 5th)
  4. Hawthorn (down from 3rd)
  5. Richmond (down from 4th)

The latest Team Dashboard provides some Scoring metrics to support these assessments:

  • Fremantle has conceded the fewest Scoring Shots per game, West Coast the second-fewest, Hawthorn the third-fewest, and Sydney the fourth-fewest
  • Sydney's opponents have the lowest Scoring Shot Conversion rate, Richmond's the second-lowest, and Fremantle's the fourth-lowest

Offensively, the Top 5 teams are now:

  1. Hawthorn (up from 2nd)
  2. West Coast (down from 1st)
  3. The Kangaroos (no change)
  4. Collingwood (up from 8th)
  5. Geelong (down from 4th)

Dropping out of the Top 5 this week was GWS, who plummeted to 11th despite not taking the field, a victim of unfavourable reassessments of the defensive merits of GWS' previous opponents.

Again, the latest Team Dashboard offers some quantitative supporting evidence for these rankings:

  • Hawthorn has recorded the highest number of Scoring Shots per game, West Coast the second-highest, and Collingwood the fifth-highest
  • Geelong has the second-highest Scoring Shot Conversion rate, Collingwood the third-highest, West Coast the fourth-highest, and Hawthorn the sixth-highest.

Seven teams now differ in their ODM Defensive and Offensive Rankings by more than three places:

  • Essendon (Ranked 7th on Defense and 16th on Offense)
  • Fremantle (1st and 10th)
  • Geelong (13th and 5th)
  • The Kangaroos (12th and 3rd)
  • Port Adelaide (8th and 12th)
  • Richmond (5th and 10th)
  • Sydney (2nd and 9th)

For five of those teams, the exceptions being Essendon and Port Adelaide, their competition ladder position is nearer their Defensive Ranking than their Offensive Ranking. This bias toward Defensive Ranking being a stronger indicator of competition ladder position than Offensive Ranking is also true amongst the teams currently in the Top 8 competition ladder position where we find:

  • Five teams have Defensive Ranking nearer competition ladder position (Fremantle, Sydney, Hawthorn, Richmond and the Western Bulldogs)
  • Two teams have Offensive Ranking nearer competition ladder position (Adelaide and West Coast)
  • One team has Offensive and Defensive Ranking equidistant from its competition ladder position (Collingwood)

This is also consistent with what we see in the Scoring Shot data from the Team Dashboard from which we can calculate that the rank correlation between competition ladder position and Scoring Shots Conceded per game is a high +0.92. (The rank correlation with Scoring Shots Generated per game is only +0.79.)

PREDICTIVE ACCURACY

ChiPS, Colley, ODM and MARS all Rated five of the six winners more highly than their respective opponents this week, while Massey and the two ODM Components Rated only four of the winners more highly.

That leaves ChiPS and MARS level on the number of correct predictions for the year, ODM and the ODM Offensive Component trailing by 9 tips, Massey trailing by 10, the ODM Defensive Component trailing by 11 tips, and Colley trailing by 15 tips.

ChiPS' and MARS' accuracy rate, ignoring Round 1 where all Systems were credited with 4.5 wins from 9, now stands at 69.7% (69 from 99). That's identical to the TAB bookmaker's record over those same games.