Where it all begins
Centre bounces are one of the things that sets Australian football apart. Not so much for the novelty of the bounce, but because after a major score possession is reset to neutral. In most sports play restarts with the ball in possession, whether alternating (e.g. netball) or given to the team who conceded (e.g. basketball, soccer).
That makes centre bounces an incredibly potent weapon. There aren’t any brakes that the rules applied, only what the opposition can summon. A patch of dominance can reshape the course of a game in mere moments.
Who’s delivering at centre bounces this year then?
Getting the clearance isn’t the only way a player can contribute at a centre bounce. First possession is important, rucks can add a lot through hitouts to advantage, and defensive pressure is critical. For the purpose of a single number to measure impact though clearances work pretty well.
As expected, down the bottom right in the “high attendance, low clearance” group we see the primary rucks. Solo rucks are there 80% or more of the time, but they’re generally not going to be winning clearances themselves at a high rate.
Above that we’ve got some of the other heavily used midfielders. Caleb Serong stands out among them as the only player attending a high number of clearances to keep a clearance rate (clearances / bounces attended) above 15%.
The top left is where things probably get the most interesting. We’ve got three players who have attended (relatively) few bounces this year but when they do are making things happen at an alarming rate.
Going back as far as 2021 (and limiting only to players with 100+ CBAs in a full season (or 75+ so far this year), Nasiah Wanganeen-Milera, Joel Freijah, and Cam Rayner are the only players to have a clearance rate above 20% across a season (Paddy Dow finished with exactly 20% in 2023).
How these three got to their CBA numbers is quite different though.
Wanganeen-Milera has had four games with 40%+ attendance, including 79% last week, his other 14 games have seen two in the 20s, three below 10%, and the rest with no attendances. It seems clear the Saints are looking to build into him the capacity to be an elite primary midfielder, rather than a half-back who rotates through.
Freijah on the other hand has seen between 20% and 40% of bounces in 11 of his 18 and attended at least 5% every week. Rayner is somewhat similar, although with a higher floor and lower ceiling, all of his games falling between 7.7% and 25%.
This brings us to the question of how teams are sharing the load more generally.
The chart is ranked in ladder order as of the end of round 19. Teams where the dark colour extends further right represent a higher concentration of CBAs among a smaller number of players – for example 93% of Brisbane’s CBAs have been taken by 6 players – Neale, Dunkley, McCluggage, Ashcroft, and the two rucks in Fort and McInerney. By comparison Essendon and West Coast use 13 and 12 players to fill out the first 93% of CBAs.
What does it mean to have a settled centre bounce lineup? To be able to distil down into a single number I’ve chosen a measure of what % of centre bounce attendances are filled by the first 8 players across a season. This is arbitrary to an extent, but looking through the data appeared to give a reasonable point of separation between teams. It then allows us to compare it to an output – centre clearance differential.
We can see two things. Firstly a higher proportion of CBAs from a core group appears to correlate to a better centre clearance return. This matches intuition, one of the primary drivers of a high concentration of CBAs is health. Having your top tier midfielders available throughout more of the season will naturally yield better results.
The second is that over the last 5 seasons CBAs have become more concentrated among a smaller group of players. Four of the 9 most concentrated CBAs occur this year – although for very different ladder results with the teams being Brisbane, Adelaide, Melbourne, and North Melbourne.
We also see Richmond and Port Adelaide as the most concentrated teams to have averaged a -1 differential or worse further showing that consistency alone isn’t a guarantee of even centre bounce results.
