As West Coast Eagles racked up yet another big free kick tally win at Subiaco despite losing to Melbourne on the weekend, we began to ponder whether the ‘noise of affirmation’ is real.
What is the ‘noise of affirmation?’ It was a phrase coined by St Kilda coach Alan Richardson early this year to try and explain the 8-23 free kick his team faced in their loss to the Eagles in Perth in Round 2.
The concept is that a vocal home crowd has the capability to influence the decision making of umpires because the noise creates pressure on them.
It raised an interesting point, whether home teams enjoyed an advantage when it came to winning free kicks.
The perception is that in places like Subiaco, Adelaide Oval and Skilled Stadium, the home team enjoys the ‘rub of the green’. Is that perception reality? It would appear so.
The raw numbers paint an interesting picture. In terms of pure free kick advantage, West Coast lead the pack at Subiaco in 2017. They average 6.85 free kicks more than their opposition in the seven games they have played at their home venue this year.
Second-best of the teams we examined was the Bulldogs, who average 5.85 more free kicks than their opposition when they play at Etihad Stadium.
Sydney, traditionally one of the worst performing teams when it comes to winning free kicks, also fare well when playing at their home, the SCG, with an average of 3.14 free kicks more than their opposition per game.
The two Adelaide teams are both in the positive when at home, with the Crows at +2.5 and the Power at +2.67 at Adelaide Oval.
The crowd influence at Kardinia Park is not as pronounced as the perception would indicate in the free kicks stats, with the Cats enjoying an average of +2.5 free kicks per game in their four games at home this season.
However, looking at pure plus or minus in terms of free kicks at home is only so useful. That doesn’t account for the fact that a team may tend to win or lose a lot of free kicks anyway because of the way that they play.
So in order to determine the true impact of the noise of affirmation, we have compared a team’s home free kick record with its record of conceding and winning free kicks away and the results raise some eyebrows.
The H/A FK differential is the best measure of this. It is the difference between the average free kicks conceded by a team at home per game, to those conceded away.
Two teams clearly stand out on top in the H/A FK differential, Sydney and West Coast.
As mentioned, Sydney fare poorly when it comes to winning free kicks and are currently 16th in Footy Prophet’s AFL Free Kick Ladder, with just four FK tally wins for the year.
While they average -5.57 in the frees for v free against column away from home, it is +3.14 at the SCG. That means that there is an 8.71 positive differential per game for them at the SCG.
West Coast’s H/A FK differential is also extremely high at +8.52 and they sit in a clear second place. In third place are Port Adelaide with +5.33, just ahead of Fremantle on +5.30 and Western Bulldogs on +5.02.
Geelong’s H/A FK differential is +4.83, while Adelaide is +3.88.
What is of course interesting is the proliferation of interstate teams at the top of the list. Is this a long-term trend? We don’t yet know, but we’ll keep crunching the numbers and provide you with the results.
Meanwhile, here is this week’s Free Kick Ladder with the Western Bulldogs back on top, and the Eagles moving into second courtesy of their sixth home win of the season.
|18||Greater Western Sydney||13||4||8||1||18||211||256||82.42%||0|