Malcolm Mackerras: Commenting on elections for the best part of 50 years. Credit:Lyn Mills From 1949 until 1983 the Senate ballot paper required voters to fill in consecutive numbers for every box next to every candidate. That way at each Senate election five, and from 1984 six, senators would be elected from every state under a proportional representation system. The quota for a Senate seat is 14.3 per cent and can comprise primary votes and preference flows. The PR system avoided the "tyranny of the majority", which had a winner-take-(almost)-all effect. For instance, from 1946 to 1949 there were only three opposition senators – a leader, a deputy leader and a whip, facing 33 government senators. With apologies to Paul Keating, that setup was truly an unrepresentative swill.

While the candidates representing a political party are identified as such, optional preferential voting for a limited number of candidates is not allowed. With more and more parties and candidates standing for the Senate, the informal vote crept up to 9.9 per cent in the 1983 election (11.1 per cent in NSW) – equivalent to almost a full Senate quota. Reform under Hawke The newly elected Hawke government tackled Senate voting reform and, with bipartisan support, it implemented the system we have today. Since 1984, voters can simply place a '1' above the line for the political party or group representative, or alternatively, undertake the onerous task of numbering every box below the line. With 85.7 per cent of voters choosing the above-the-line option, the 1984 election saw the percentage of Senate informal votes plummet to 4.3 per cent.

Fixing the problem of a high informal vote in the Senate has been replaced with something more insidious – a system that's gamed, and voters treated as "mug punters". In 2013, the informal vote was down to 3 per cent, with 96.5 per cent voting above the line. But this drop in the informal vote came at a price, arguably to the democratic will of voters. Political parties were given the power to lodge "group voting tickets", which direct voter preferences at their whim. Despite the fact that such GVTs need to be displayed at polling booths and published online, I suggest almost all voters have no idea where their above-the-line vote could end up.

And that is something that the backroom operators of political parties and the so-called preference whisperers have been banking on for years, and more so in recent elections. Many pollies like referring to voters as "punters", and the Senate voting system has shown what a lottery it has become. Most Greens' voters would be bemused that the party of coal miner Clive Palmer helped get SA Greens senator Hanson-Young elected in 2013. More bizarrely, in SA it was Labor and Greens preferences that helped Family First's Bob Day – a party well to the right of the Liberal Party – get elected with just 3.7 per cent of the primary vote. I can't imagine too many Labor or Greens voters thanking the party apparatchiks who did that.

Mug punters It seems that after 30 years, fixing the problem of a high informal vote in the Senate has been replaced with something more insidious – a system that's gamed, and voters treated as "mug punters". The solution I propose, that Mackerras is so implacably opposed to, is to get rid of GVTs by giving the power back to voters. My proposal calls for voters to number at least three consecutive numbers above the line, or at least 12 below – their choice – not that of party machines or preference whisperers. This proposal is broadly based on the ACT voting system, which has proved to be robust and fair.

Mackerras is right to suggest I am cranky about the 2013 Senate result – over 258,000 South Australians, almost 25 per cent of the state's vote, supported what I, and my running mate Stirling Griff, stood for. Instead, over 110,000 South Australians saw their votes go nowhere because of sneaky and inexplicable preference deals. Mackerras says that as a psephologist, an election predictor, he gets it right two out of three times. "The election analyst who makes predictions is far more interesting than one who doesn't," he says. "And if I collect egg on my face, so be it." Loading Here's my prediction. Not only is Mackerras wrong with his resistance to sensible Senate voting reform, he could well end up with one massive omelette on his face.

Nick Xenophon is an independent senator for South Australia and leader of the Nick Xenophon Team political party, which will run candidates at the next federal election.