MARS altered its view about the ranking of just three teams this week, demoting Essendon and Fremantle by one spot each and elevating Richmond by two, mainly on the basis of the unexpectedly large victory by the Tigers.
MARS' interquartile range - the Ratings gap between the teams ranked 4th and 15th - grew yet again to reach a season-high 69.0 Ratings Points (RPs), while the gap between the teams ranked 4th and 8th shrank to just 14.0 RPs, the lowest it's been since Round 16. A season-high 12 teams are now ranked above 1,000 and there's a cavernous 26 RP gap between Fremantle in 12th and the Lions in 13th so there's virtaully no hope of another team joining the "above-average" club anytime before season's end.
Four teams have gained around 10 RPs or more over the past five rounds, the Hawks, Roos, Freo, and the Swans, each of which has won in four of those five rounds and, in the case of the Roos, has won in all five.
Five other teams have been net RP acquirers across this period, though their ability to accumulate competition points has been more variable, ranging from just two wins for the Tigers to four wins for the Crows and the Pies.
Another five teams have surrendered about 10 RPs or more during this five week period, averaging just one win each in so doing. The Eagles have fared best by registering two wins while the Dogs have fared worst in losing five straight.
The Giants, Suns, Blues and Dees have been the competition's other net RP losers on MARS, each dropping 4 RPs or fewer and each having recorded one or two victories during the past five rounds.
MARS' re-ranking of just three teams is, as usual, at the more stable end of Rating System behaviour, bettered only by ODM's re-ranking of just two teams, Collingwood and St Kilda, each by a single place only.
Massey was only slightly less capricious in its re-ranking, switching just four teams, but it re-ranked each of them by two ladder spots: Essendon down two spots to 10th, Freo down two spots to 11th, the Roos up two spots to 8th, and the Tigers up two spots to 9th.
Colley, a little unusually, was the System most eager to punish and reward teams for their perceived successes and failures in Round 20, re-ranking seven teams, three of them by more than a single spot: Collingwood up two spots to 1st and the Swans down two spots to 3rd, as well as the Roos up two spots to 7th.
Teams for which the Ratings systems differ in their rankings by three places or more are now:
- Adelaide (2nd on the ladder): ranked 2nd by Colley, 3rd by Massey and ODM, and 6th by MARS
- Carlton (11th on the ladder): ranked 9th by MARS, 10th by Colley and ODM, and 12th by Massey
- Essendon (8th on the ladder): ranked 8th by ODM, 9th by Colley, 10th by Massey, and 11th by MARS
- Fremantle (9th on the ladder): ranked 8th by Colley, 9th by ODM, 11th by Massey, and 12th by MARS
- Geelong (7th on the ladder): ranked 4th by MARS, 6th by Colley, and 7th by Massey and ODM
- Hawthorn (4th on the ladder): ranked 1st by Massey, ODM and MARS, and 4th by Colley
- Kangaroos (6th on the ladder): ranked 7th by Colley, 8th by Massey and MARS, and 12th by ODM
- Richmond (12th on the ladder): ranked 9th by Massey, 10th by MARS, 11th by ODM, and 12th by Colley
- St Kilda (10th on the ladder): ranked 5th by ODM and MARS, 6th by Massey, and 11th by Colley
Looking at the ability of the Rating Systems to predict winners commencing in Round 5, where each System's predictions are based solely on the team they rank higher in a given game, we now have:
- 1st: MARS 102/135 (76%)
- 2nd: ODM and Colley 98/135 (73%)
- 4th: Massey 97/135 (72%)