In a Senate election that has excited more interest than most, there has been a lot of understandably confused talk over the past few days about the impact of contentious preference decisions. What follows is an attempt to sort through some of them claims which have gained currency around the place.

Claim: Wikileaks preferences cost Scott Ludlam his seat.

Julian Assange has had no more stout defender over the past few years than WA Greens Senator Scott Ludlam, so his party’s failure to fast-track preferences to Ludlam provoked a furious response from many, not least his own mother. Most offensive to left sentiment was the decision to place Ludlam behind David Wirrpunda of the Nationals, which the party justified as supporting Aboriginal representation. When news came through that Ludlam had indeed fallen short (pending of course a possible recount), many on social media jumped to the conclusion that Wikileaks was to blame.

However, the potential of Wikileaks preferences to harm Ludlam actually went unrealised. Wikileaks preferences did flow to the Australian Sports Party and the Nationals in turn, but both were eliminated fairly early in the count. Since Ludlam had a higher placing from Wikileaks than the other late count survivors, namely the two major parties, the Palmer United Party and Shooters and Fishers, he did in fact get their votes – 8150 of them, which in the final analysis still left him 3372 short of Louise Pratt.

Claim: Wikileaks vote-splitting cost Scott Ludlam his seat.

Absent the opportunity to blame Wikileaks for their preferences, some of the party’s critics fell back on the argument that it damaged Ludlam by fielding a candidate at all. One such was Mary Kostakidis, who like many expressed her displeasure on Twitter. This would have been a telling point under first-past-the-post, but it doesn’t work so well under compulsory preferential voting, where every vote of an excluded candidate ends up with somebody else – in this case, as noted, the Greens. If anything, Wikileaks’ entry might have helped deliver the Greens preferences from libertarians who would never have voted for them directly, although I doubt there would have been much in this. It could be argued that the absence of a Wikileaks candidate might have given Ludlam’s campaign clearer air, but I doubt there’d be much in that either.

Claim: Greens preferences elected Family First in South Australia.

Confronted with the allegation that her party’s preferences were responsible for electing Bob Day of their ideological enemy Family First yesterday, Sarah Hanson-Young tweeted: “Actually SA Greens preferences went to Xenophon & Labor well ahead of both FF & Liberals”. Either the Senator was not entirely on top of her own preference ticket, or she was being exquisitely disingenuous – perhaps the former, given that her tweet was deleted shortly thereafter. It was indeed true that Xenophon himself was rated much higher than Family First on the Greens’ preference ticket, but as Xenophon had no trouble getting elected off his own bat, that was beside the point. The issue was Xenophon’s running mate Stirling Griff, who did spectacularly badly on preferences from all fronts. Whereas Xenophon was given a solid but ultimately irrelevant position a third of the way down the Greens’ preference order, Griff was buried deep below. As it happened though, the 11,065 Greens ticket votes delivered to Day after Hanson-Young’s election were surplus to requirements: he would still have been 21,257 clear of a quota without them. So the Greens did not of themselves elect Family First, though it wasn’t for want of trying.

Claim: Labor preferences elected Family First in South Australia.

By contrast, Bob Day would never have made it had not Labor also opted to put him ahead of Stirling Griff. This might inspire comparison with Labor’s preference decision in Victoria in 2004 which gave Steve Fielding his seat at the expense of the Greens, but on this occasion Labor had the Greens second. The decisive factor was actually the transfer of Sarah Hanson-Young’s surplus, which was bloated with the Labor preferences received when Don Farrell was eliminated. This amounted to 41,501 Labor ticket votes which would have elected Griff had they been directed to him instead.

The wonks among you might like to observe that this is an uncommonly severe case of the distortion caused by the “inclusive Gregory” method of calculating transfer values when distributing surpluses. In theory, those Labor votes shouldn’t have been worth so much since they have already been used to help elect Penny Wong. However, the existing system only applies one transfer value to all votes in a given surplus distribution. If votes were reduced in value in due proportion each time they formed part of a surplus transfer (the “weighted inclusive Gregory” method), the Hanson-Young transfer would have contained 23,390 Labor and 18,214 Greens ticket votes, rather than 41,501 and 11,065. In that case, Labor preferences of themselves would not have been decisive.

The value of Labor votes was again inflated when Bob Day’s surplus was distributed, at which point Labor’s remarkable decision to place Griff behind even the Liberals kicked in. This wasn’t decisive, but it might have been if the gap between Simon Birmingham and Griff had been a little narrower. Another factor to be kept in mind here is that Labor got a bigger bang for its buck out of its preference ticket decisions, since 90.8% of its votes were above-the-line against only 81.4% for the Greens.

Claim: Nick Xenophon started it by shafting the Greens.

The Greens’ motivation to punish Nick Xenophon even to the point of aiding Family First was his own decision to preference the major parties ahead of the Greens. Hanson-Young was heard to complain that Xenophon was “making a political decision, just like any other politician”. However, it seems to me that Xenophon is the only party in all this who was doing just the opposite, his preference tickets appearing at least outwardly to be all principle and no expediency.

The Senate ticket voting system allows groups to have up to three preference tickets for their above-the-line votes to divide evenly between. Xenophon used this to play the straightest possible ideological bat by having one ticket that looked how a moderate left supporter might want it to look, and another pleasing from the perspective of a voter of the moderate right. This meant one of his tickets did in fact have the Greens ahead of the Coalition parties, while the other had them behind both the Coalition and Labor. So the Greens might in fact have received half of Xenophon’s preferences, had those preferences been distributed at a point where there was no Labor candidate in the count. In the event, Xenophon preferences were not distributed at all, as Stirling Griff was left holding the bag when Simon Birmingham was elected at the final count.

The Greens’ sense of grievance that Xenophon’s idea of moderate tickets should place them behind Labor is no doubt informed by the fact that he played it differently at his first Senate election in 2007. Xenophon’s idea of ideological balance at that time was to have a single preference tickets which placed the competitive minor parties of both right (Family First) and Left (the Greens) ahead of the majors. I wouldn’t care to venture if Bob Brown spoke truly when he claimed Xenophon’s objective this time around was to loom larger on a smaller cross-bench (a goal he has spectacularly failed to achieve if so). But if he was wrong and Xenophon was indeed motivated by principle, he offers a useful case study for why so few others followed suit. Despite scoring something between six and seven times as many votes, Xenophon landed the same number of seats as Family First. Stirling Griff started the preference distribution process with 107,110 votes, seemingly well on his way to the quota of 148,348. But as preferences swelled the Family First base vote from 38,909 all the way to 180,670, Griff was only able to limp to 121,743.