Tie votes in STAR Voting are rare - well over 10 times less common than with choose-one voting - but as with any voting method they can occur, especially in small demos or elections without many voters.

Establish tie-breaking protocols in advance

The body hosting the election is responsible for establishing tie-breaking protocols in advance of its elections.

In the event that an election has already been conducted but no protocol was specified, and an election tool that handles ties automatically wasn't used, the Simple Tiebreaker Protocol below should be used. We also recommend the Simple Tiebreaker Protocol for hand counted elections hosted by volunteers or lay people because of its simplicity and transparency.  

Otherwise, we recommend the Official STAR Voting Ties Protocol, which is the stock implementation included on all STAR Elections voting platforms. The official protocol is a bit more complex, but is exceptionally good at breaking ties wherever possible, even in small elections with only a few voters. 

Simple Tie-breaker Protocol:

Step 1: If two candidates receive the same total score in the scoring round, the tie should be broken in favor of the candidate who was preferred (scored higher) by more voters, if possible. 

Step 2: Ties in the Runoff Round should be broken in favor of the candidate who was scored higher if possible.

Step 3: In the event that a tie can not be resolved as above, the tie will be broken randomly with a method such as a coin toss or by drawing a name out of a hat.

Official Tiebreaker Protocol:

Step 1: Ties in the scoring round should be determined in favor of the candidate who was preferred (scored higher) by more voters. If there are only two candidates this will be the majority preferred candidate. If there are multiple candidates who are scored equally, ties are broken by comparing the tied candidates head to head and eliminating the candidate(s) who lost the most match-ups. This can be repeated with the remaining tied candidates as needed until two candidates can advance to the runoff. 

Step 2: Ties in the Runoff Round should be broken in favor of the candidate who was scored higher if possible.

Step 3: In the event that a tie can not be resolved as above, break the tie in favor of the tied candidate who received the most five star ratings. If this does not fully resolve the tie, eliminate the candidate(s) with the least five star ratings.

Step 4: In the event that a tie can not be resolved as above, the tie will be broken randomly with a method such as a coin toss or by drawing a name out of a hat. If needed, repeat the tiebreaker protocol from the top with remaining tied candidates until the election is complete. 

What is a preference matrix and why might I need one?

A preference matrix is a chart which shows all the voter preference data from a given election. In most elections a full matrix isn't needed. All that is needed to select the winner is to determine the preferences between the two highest scoring candidates.

A preference matrix is a great reference point for looking at the additional data which can be gleaned in STAR elections. It may also be helpful for breaking ties in the scoring round. 

Another reason a matrix might be needed is if ballots are not being tallied centrally, or if ballots will be counted in sets as they come in. Creating a matrix for each sub-set of ballots allows each set to be fully tallied on its own and then be compiled with other sets of ballots later. This is a feature known as summability. Ballot summability means that with STAR Voting local audits and/or partial recounts are possible if needed. Summability is an important requirement for election security and integrity. STAR Voting and most voting methods are summable, but Instant Runoff voting, the type of Ranked Choice widely used around the world, is not.

Preference matrices provide a lot more information beyond who won and lost, so they are often used in data analysis. One advantage of STAR Voting over choose-one is that all of this additional data is available.

How do I create a preference matrix?

Unless you are doing a hand count, a matrix can be generated automatically and will usually be available with your election results, depending on the platform you're using.

Creating a preference matrix by hand is just like tallying a STAR election, but with an extra runoff for each pair of candidates:

• Total the scores given to each candidate in the election.
• Just like in the STAR runoff, the two highest scoring candidates are selected. Sort the ballots to find how many voters preferred each of those finalists. Ballots are sorted into three stacks: Ballots preferring one finalist, ballots preferring the other, and ballots who gave both the same score and thus have no preference between those two.
• If you are doing a hand count you will likely have found your winner and can stop here, completing a full preference matrix is completely optional. In the example below Allison won with 35 points. She was preferred by 8 out of 10 voters, or 80%.
• To create a full preference matrix, repeat the step above for each pair of candidates, for example, Allison vs Bill, Allison vs Carmen, and so on. Record the number of ballots which preferred each candidate in each head-to-head match in the corresponding box. 

Tiebreaker Example #1: 

In the example above we have a tie in the scoring round. Bill and Carmen are tied for 2nd highest scoring candidate with 32 stars each so we'll need to break the tie to determine who should advance to the runoff. Looking at the preference matrix we can determine that Bill is preferred over Carmen, (five voters prefer Bill over Carmen, but only four voters prefer Carmen over Bill,) so this is a simple tie that can be easily resolved. Bill advances to the runoff. 

In the runoff, we find that Allison and Bill are both preferred by the same number of voters, (5 each,) but looking at the scores we find that Allison was scored higher overall so this is another simple tie that can be easily resolved. Allison wins the election.

Tiebreaker Example #2:

In the example above, Allison, Bill, Carmen, and Doug are all tied for highest scoring with 78 stars each. Looking at the preference matrix we find that there is a three way tie in the runoff as well! Allison is preferred to Bill, Bill to Carmen, and Carmen to Allison. Doug is not preferred over any of the others so he is not one of the tied candidates.

Ties like these will be broken by a random tie-breaker if you are using the Simple Tiebreaker Protocol above, but using the Official Tiebreaker Protocol it may be possible to break the tie by referring back to the ballots themselves. In this case you would look at the ballots cast and see how many voters gave Allison, Bill, and Carmen a top score of 5 stars. The candidate with the most 5 star ratings will win the tiebreaker.  

If you are running an election and have additional questions or would like guidance please email us at [email protected].

If you are interested in open-sourced code to help you implement STAR Voting on your website or platform please email us at [email protected] so we can help.