Maxime Bernier is the favourite to finish atop the first ballot for the Conservative leadership, but an analysis of how the vote could play out suggests that it could take all 13 ballots before a winner is finally declared.

And while Bernier remains the favourite to win it all, his path to the leadership is far from certain.

The next leader of the Conservative Party will be decided by a preferential vote, in which members can rank up to 10 of the 14 candidates on the ballot.

Points will be awarded according to the share of votes candidates receive in each of Canada's 338 ridings. Unless one candidate has a majority of points, the candidate with the fewest points nationwide is eliminated and their votes redistributed to their supporters' next preference. This process continues until one candidate reaches a majority.

It is possible to estimate the first ballot result based on available data (fundraising, polls and endorsements). The Conservative Leadership Index, the latest edition of which can be found at the bottom of this article, does just that.

Where the vote will go after the first ballot is more difficult to figure, but it is possible to get an indication of voters' preferences from fundraising data.

A significant proportion of donors contributed funds to more than one candidate, suggesting that they are likely to rank these candidates highly on their ballot — and presumably like-minded voters will do the same.

Scheer, Bernier with second choice potential

An analysis of fundraising between Jan. 1 and Mar. 31 shows that Bernier and Scheer share the most donors with the most other candidates.

Bernier topped the list among donors to Michael Chong, Kellie Leitch, Erin O'Toole and Lisa Raitt. Scheer was the top candidate among donors shared with Bernier, Chris Alexander and Rick Peterson, while O'Toole was first amongst Andrew Saxton's donors.

Bernier and Scheer ranked highly among other candidates as well.

The most significant overlap was between Trost and Lemieux, two social conservatives. Fully 41 per cent of Trost's shared donors contributed to Lemieux's campaign, while 28 per cent of Lemieux's shared donors contributed to Trost's.

It is possible that some of these shared contributors paid fees for fundraising events attended by multiple candidates, though the data does not suggest that those donors represent a significant proportion of the whole.

Less than 15 per cent of donors who contributed to the campaigns of Bernier, Chong and Leitch gave money to another candidate. Contributors to Blaney or Trost were the most likely to have given to someone else, representing 42 and 37 per cent of these two candidate's donors, respectively.

Going ballot by ballot

Using this data to estimate the preferential ballot and potential dropped ballots (if voters only mark their first choice), as well as combining it with the Conservative Leadership Index and an analysis of each candidate's distribution of support by riding, it is possible to simulate how the vote could break down ballot by ballot.

This is not a prediction of the outcome, but rather an illustration of what implications the preferential ballot could have on deciding the winner.

The first few ballots do not have a big impact. Combined, Deepak Obhrai, Peterson, Alexander and Saxton are estimated to take just 4.6 per cent of the points. By the sixth ballot (assuming Kevin O'Leary, whose name will be on the ballot, is among the first to drop off) no remaining candidate could be more than a point further ahead.

The seventh ballot, which in this scenario redistributes Blaney's 2.9 points, primarily boosts Lemieux and Leitch. If Blaney performs better in Quebec, however, he could find himself surviving beyond the seventh ballot.

On the eighth ballot, Trost sends most of his points to Lemieux and a significant proportion to Scheer. This pushes Lemieux past Chong in the rankings and narrows the margin between Scheer and Bernier. Raitt is eliminated.

On the ninth ballot, Bernier, Scheer and O'Toole receive a bump from Raitt — but Chong does not get enough of a boost to push him past Lemieux and save him from elimination.

Simulation of Conservative leadership ballot

On the 10th ballot, Bernier and O'Toole gain the most from Chong's ouster, Lemieux and Leitch the least. Along with Raitt's elimination this could be an opportunity for O'Toole to move ahead of Scheer. But both are still well behind Bernier who, at 32 points, remains far from a majority.

Lemieux drops off and on the 11th ballot a big share of his support goes to Scheer, allowing him to further close the gap on Bernier and widen the margin between him and O'Toole. It is possible that Lemieux could instead give a greater boost to Bernier, who has emphasized during his campaign that under his leadership social conservatives would be free to express their views.

With the elimination of Leitch on the 12th ballot, Bernier still leads with 38.4 points, but Scheer (33.6 points) and O'Toole (28 points) are not far behind.

Leitch's voters could play a decisive role. They are a large enough group that they could decide who between Scheer and O'Toole goes head-to-head against Bernier. If a big enough number of them instead opt for Bernier, his win would be all but assured.

In this simulation it is O'Toole who drops off the 13th and final ballot. The fundraising data suggests that Bernier and Scheer split his voters, giving Bernier the win with 52.9 points to 47.1 points for Scheer. Bernier's wide advantage in Quebec, where he wins 74 per cent of the points, gives him the victory.

Endless possibilities

But this simulation presents a close enough margin — and alternative turning points — for it to easily go Scheer's way (or O'Toole's, if he is the last man standing with Bernier). In order to win in this simulation, Scheer would need to take 60 per cent of O'Toole's points. That is achievable. Bernier would need a bigger margin by the penultimate ballot to hold off a consolidation of Scheer's and O'Toole's voters.

It would not take much else to change the outcome. Greater support for and from Lemieux and Trost could put Scheer in a better position by the final ballots. O'Toole could over-achieve with significant support from Raitt's and Chong's voters. With a better first ballot result or more second choice preferences throughout the count, Bernier could put himself out of reach earlier on — maybe even winning before the 13th ballot.

Bernier has raised the most money during this campaign and is polling ahead of his rivals. He is the favourite going into Saturday's vote. But that shouldn't dampen any of the suspense before the winner is announced.

Conservative Leadership Index, May 22

The index is based on four different metrics: endorsements, fundraising, contributors and polls. In tests on 14 recent federal and provincial leadership races in which all party members could vote, the index has replicated the first ballot results with a median error of +/- 2.2 points per candidate.

A more detailed explanation of the index's methodology can be found here.