Matter of Stats

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AFLW 2022 Spring Edition - Round 9 - Results

Another solid week for WoSHBODS, with season second-bests for Margin MAE (14.3 points per game), Totals MAE (9.7 points per game), and LPS, and a 7 from 9 result on accuracy, all of which has led to the table below.

We can break down that overall Margin MAE of 19.0 points per game into team-by-team contributions, which we do in the table at right and which shows that WoSHBODS has been particularly precise in game margins for matches involving the Dogs, Pies, Dees, Tigers, Blues, and Hawks, and particularly imprecise in game margins for matches involving the Giants, Swans, Crows, and Saints.

Looking solely at the four expansion teams, we have Hawthorn and Essendon well under the all-team average, Port Adelaide at just over the average, and Sydney much higher than the average.

Altogether, 10 teams have MAEs below the all-team average, and eight have MAEs above the all-team average.

We can also break down the overall Margin MAE based on the size of the eventual victory, which we do in the table at left and which shows that, still, it has been the larger victories where the forecasts have been least accurate, and the narrower victories where they have been most accurate.

What’s also true is that WoSHBODS has tended to be more accurate in games that were won by relatively large margins. It is 23 from 39 (59%) in games won by under 3 goals, and 35.5 from 42 (85%) in games won by 3 goals or more.

The Log Probability Scores can also be analysed by team, and the results of doing this are shown in the table at right where we assign one half of the LPS for a game to each of the two teams.

Here we see that WoSHBODS’ probability estimates have resulted in strong LPS returns from the Dogs, Dees, Swans, and Dockers, and weak returns from the Saints, Eagles, Blues, and Tigers. Richmond’s surprise victory over the Lions in Round 5 was a significant contributor to the especially low total for the latter.

Overall, there have been positive LPS contributions from 13 teams, and negative contributions from five teams.

The Ranking on Team Metrics table appears below and continues to show the relative unimportance of Own Scoring Shot Conversion this season, with the Top 8 teams on the ladder now including four of the bottom five teams on that metric. We also see that Opponent Scoring Shot Conversion isn’t now a great deal more important.

Those two metrics aside, there are reasonably high correlations between ladder position and ranking on all other metrics, with only Q1 Performances showing a correlation below +0.79.

Lastly, here is the full Team Dashboard, which shows that:

  • Essendon, who sit 10th, have scored more goals than four of the teams in the Top 8 in the ladder

  • Gold Coast are in 9th but have a 90 percentage

  • Geelong have scored fewer goals that the four teams directly below them on the ladder

  • Sydney have scored just under half their points in Q1s

  • Carlton have scored 40% of their points in Q1s

  • Fremantle have conceded about two-thirds of their points in Q2s and Q4s

  • Brisbane Lions have conceded almost 75% of their points in Q1s and Q3s

  • Sydney have won only 4 quarters all season (and none in Q3), which is six fewer than any other team

  • Sydney have been outscored by their opponents roughly 3:2 in Q1s, 3:1 in Q2s, and 4:1 in Q3s and Q4s

  • Brisbane Lions and Melbourne have won 25 of their 36 quarters, and Collingwood and North Melbourne have win 24.