Response: Are Adelaide winning the Dangerfield trade?

I wanted to provide a response or an addendum of sorts to Ryan Buckland’s article; ‘Are the Adelaide Crows winning the Patrick Dangerfield trade?’.

Partly, I was mildly let down because I felt there wasn’t really an evaluation of who had done better. More so, the article sort of looked at which team had performed better since Dangerfield left. There are a couple of specific things I’d like to address in respect to that article.

Firstly, how do we measure who won? I suppose Ryan is saying if Adelaide have been the better team or continue to be (betting markets predict they will be in 2019) then you could argue the Crows won the trade.

The conclusion of Ryan’s article seemed to answer a different question – ‘Was it good for Dangerfield to leave?’

To me, that’s a separate question. Ryan also referred to Dangerfield staying as an impossible counterfactual and suggested that Adelaide would’ve won the 2017 grand final with Dangerfield.

Well – I don’t think the counterfactual is impossible to unpack. I also agree that, at the very least, we could say Adelaide would be more likely to win or that their likely performance would’ve been better in that 2017 decider, although showing how one player would’ve affected a solitary game is hard to do.

So anyway, I try to quantify player performance. I have written a couple of articles looking at offensive and defensive efficiency and I will use those methods in this analysis so if it doesn’t make sense you may need to go back to those articles as a primer.

To me the essential questions are;

• Has the Dangerfield trade brought more value to Geelong or Adelaide?
• Who will get more value out of the trade over time?

The Trade

First, we just need to clarify what happened in the trade.

Adelaide traded Dangerfield and pick 50 to Geelong for Dean Gore, pick 9 and pick 28.

Pick 9 (which got shifted down to pick 11) yielded Wayne Milera, with Adelaide then trading pick 28 and Sam Kerridge to Carlton for Troy Menzel.

Geelong then flicked pick 50 (which, by that time, was now 53) over to Gold Coast in a three-way deal that landed them Zac Smith.

Geelong: Patrick Dangerfield. Zac Smith.
Adelaide: Wayne Milera. Troy Menzel. Dean Gore.

Who’s winning right now?

To me, this almost requires no analysis. I know people like Milera, but he is not in Dangerfield’s class. Based on my net points added per game, this is the value each player has bought to each team since being traded or drafted.

Without a common reference point, these numbers might not resonate immediately and I suspect Adelaide supporters will bristle at Milera having negative value. I will say, he’s only had one season as a somewhat effective half back and his value is hurt by two patchy years as a small forward prior to this.

Dangerfield adding almost eight points per game over the course of three years at Geelong might seem low, but let me put this in perspective. In 2016, Adelaide finished fifth with the third-best point differential in the league.

They were behind fourth-placed GWS only on percentage. If we imagine the trade never happened based on the net players coming in and out, Adelaide would’ve been on average nine points better per game while Geelong would have been 8.6 points worse off per game.

An extra 8.6 points per game would’ve given Adelaide the best point differential in the league and the second-best percentage. They also lost early in the season by ten points to North Melbourne and three points to Hawthorn. Reversing the result in even one of these games would’ve seen them finish second.

This would be the difference between having to beat North Melbourne and then play Sydney at the SCG in week 2, instead of finishing second to play GWS* in Adelaide and potentially getting a week off.

*Hawthorn finished third, but if we take a win off them in our alternate timeline because the Crows beat them instead of losing in Round 5 – then Hawthorn would drop to sixth and the other teams come up one spot – moving GWS to third. Obviously, this is where counterfactuals start to get hairy.

I’m getting sidetracked, but the point is Geelong are clearly winning the trade to date.

Will Adelaide win the trade long term?

What I’m going to do here is plot the player’s net performance against the number of games played and try and fit a trend to their output. It’s important to note that the trend is a prediction and to the best of my ability uses nearest neighbour analysis to fit the projection against similar players.

So to try and be succinct the overview of these career predictions is thus; Dangerfield is probably on the downside of his career now. You could plot certain models that suggest that decline could start occurring abruptly. I have gone with a more optimistic model that shows a gradual decline.

Ultimately if he could stay fit for long enough, I would project Dangerfield as a value-added player even up to his 400th game.

Smith, as I see it, has not really ever been value added. I believe his peak has passed and he will continue into a decline from now on.

If the Cats get the maximum out of Dangerfield’s career – and Smith plays maybe ten more games – the deal will yield something in the order of 1800 points until Dangerfield’s retirement.

The only caveats here are Smith playing more or less (I think hurts Geelong’s production) and the overall length of Dangerfield’s career. It’s worth noting Dangerfield has probably been worth 350-400 points for the Cats already.

This is probably not as helpful as we might like. What we can see is that Milera’s first two seasons as a small forward were not value-added. His previous season playing as more of a running back was still not an overall value-added, but was significantly better. This makes finding the nearest neighbour a bit difficult for Milera.

In some ways, it might be fair to even consider 2018 his first season and then compare him to a similar running back. If we incorporate his first two seasons and use polynomial regression to fit a model, like we did for the Geelong players, it would suggest that Milera will peak around game 50 and then go into decline.

I’m not sure if that is actually the way his career will pan out, but it’s worth mentioning that on the defensive metrics, Milera rates poorly.

So for the salient statistics, I have given Milera general improvement in each category as though he continues playing half back. I have been fairly generous; for example, predicting that Milera lays five tackles, has 50 per cent of his possession contested and gains almost 500 metres a game. If he improves along those lines his net production would look like this.

By this measure, he becomes about three points worth of value per game. Not too shabby and certainly above average. If we factor these expectations in, his career projection would now look like this.

Even pencilling in improvement across the board in those relevant categories, the model would suggest that Milera starts to decline at about game 110. But, if we ignore Milera’s first two seasons as a forward and pencil in that improvement, his career progression looks like this

This maps out a career where Milera becomes no value-added by about game 200 or just after, and peaks around game 130. On the basis of this reasonably generous estimation, Milera would add about 418 net points if he played a roughly 200 game career.

Unfortunately for Adelaide, the other players acquired in Dean Gore and Troy Menzel have added no value at all.

In short, unless Milera changes role again and becomes a genuinely dominant midfielder, it’s hard to imagine a scenario that Milera actually outstrips the value that Dangerfield has bought, and will likely bring, to Geelong.

I would like to dig further into the fate of the team itself and what could have been for either Geelong or Adelaide, but I have gone on a bit. Based on the value traded in and out, it would be very hard to make the case that Adelaide are better without Dangerfield or that Geelong would have been better without him.

Additionally, I noticed one commenter on Ryan’s article suggesting that Milera could win a Norm Smith Medal and then described a situation whereby Milera would play out of position in the midfield for a month and have a great finals series.

I would like to say all of those things are certainly possible. Obviously it’s hard to predict game by game fluctuations in a player’s performance. Tom Boyd would project pretty poorly based on his career arc to date but he was fairly close to Norm Smith in a premiership winning side.

My contention is that on average over time, and not weighting any single performance as more important than any other – that Dangerfield will outperform Milera when both their careers are over and for that reason Geelong comfortably win this trade.