2013 : MARS, Massey, Colley and ODM Ratings After Round 9

Again it's only mid-table movement that we see on MARS Ratings this week with no changes amongst the top 4 and the bottom 8. The middle 6 sees three pairs of position swaps as the Eagles and Crows, Dons and Blues, and Roos and Pies trade places.

The Inter-Quartile Ratings range - the difference between the Ratings of the teams Ranked 4th and 15th - is now at 39.9 Ratings Points (RPs), its second-highest value this season. As well, the difference between the Ratings of the teams in 4th and 8th is 6.5 RPs, the third-highest value this season.

Focusing solely on the last 5 rounds we find that all of the teams now Ranked in the top 9 have, in net terms, accumulated Ratings Points, while only 1 of those teams in the bottom 9, Gold Coast, has done the same.

In addition, no team's competition ladder ranking is now more than 4 spots different from its MARS Ranking, while 11 teams have a MARS Ranking that differs by no more than 1 spot from their competition ladder ranking.

For most teams this week, Rankings have become more congruent, leaving none in a position where the difference between best and worst System Rankings exceeds 6 places - which is the case for the Roos and the Eagles. For all other teams the difference is 4 places or less.

Focussing solely on ODM Rankings, we also find a trend towards divergence, the most notable exceptions being the Pies and Roos for whom the gap between Offensive and Defensive Rankings has expanded rather than contracted.

Offensive and Defensive Rankings for Fremantle and Sydney, while diverging little or no further this week, still show relative large differences.

Many teams' MARS Ratings show a uniform trend for the season to date.

In terms of predictive accuracy amongst the Rating Systems, MARS still leads the way, ahead of Massey and, now, the overall ODM System, which is marginally better at predicting winners than is its own Offensive assessments. Colley continues to languish as a predictor of victory, while the Defensive Ratings of the ODM System remain another relatively poor predictor of game outcomes.