Instant Runoff Voting and Ballot-Counting on Optical Scan Machines

Counting IRV Ballots on Optical Scanning Machine Without Any Hand-Counting/Sorting


Instant runoff voting (IRV) is an increasingly popular method of voting in the United States. As we transition to more instant runoff voting elections, our nation’s voting equipment will start to come equipped to run IRV elections. There also are tested means to conduct an instant runoff voting election on existing equipment. Here is an example of how IRV can be administered on ES&S M100 optical scan machines in an election where voters are allowed three rankings and the top two candidates advance to the runoff election if no candidate wins an initial majority of first choices. With this method, machines are used for all ballot-counting and all ballot-sorting.

Count first choice rankings: Tally first choice votes at polls, as in a vote-for-one election. Release these results. (Simultaneously, all first, second and third choice rankings are counted and those totals can be used to verify that ballots have not been changed since being counted at the precinct and being collected at the central count, as aggregate totals should match.)

Collect ballots centrally if IRV count needed: If no majority winner, collect the ballots centrally (or, if a multi-county election, in county centers that communicate vote totals to one another).

Conduct the IRV count with three machines: Re-program the feature of the machine that rejects overvotes. After re-setting software and doing Public Tests on three machines that each have been re-programmed differently, set those three machine next to one another. Use them as follows:

  1. The first machine is programmed to reject any ballot that does not rank one of the top two candidates as a first choice. It tallies the first choice totals on the remaining ballots for whichever of the top two candidates is ranked as a first choice.
  2. The rejected ballots are counted using the second machine. This second scanner is programmed to reject any ballot that does not list one of the top two candidates in the second choice column. It tallies the second choice column on the remaining ballots and counts any votes for whichever of the top two candidates is ranked as a second choice.
  3. The new batch of rejected ballots is counted using the third machine. This third scanner tallies the third choice column and counts any votes cast for one of the top two candidates.


Determine winner: The winner is whichever of the top two candidate has the most total votes tallied on each machine. Ballots are organized in batches that allow for easy manual audits of the results.