Redistricting by Shortest Splitline Algorithm Method


As frustration grows over redistricting results, many are looking for alternative methods for redrawing district boundaries without any human hand involved (so there is no chance of any funny business – also called Gerrymandering). They seek the ultimate version of an impartial system.

Among the proposals out there, the Shortest Splitline Algorithm Method seems to be gaining more attention. This is perhaps thanks, in part, to the work of Center for Range Voting (CRV).

Range Voting and Shortest Splitline

CRV has primarily focused on “range voting” where voters give all candidates running for a position an opinion score. The candidate with the highest average opinion score wins. As an aside, this does not seem like the best solution. They cite the Olympic scoring system as an example, which has been plagued by scoring controversies in recent years. Not the best advertisement for the system.

But I digress. CRV also has devoted extensive research to Shortest Splitline Algorithm Method. Basically, an area (like a state) is divided geographically in half based on the population. The result is two halves of approximately equal population. The division of halves continues until it reaches the number of districts required. There are slight tweaks to the formula if the outcome needs to be an odd number of districts.

This is perhaps an overly simplified explanation, but it gets the idea across. They provide examples of how the method resolves current district issues as well as illustrations of the method in practice for all 50 states.

They admit the solution comes with some caveats. But in looking through the research, several issues arise that seem insurmountable.

Population not exact match to Census

Census data, in its smallest form, is calculated by “Blocks”. The Shortest Splitline Method does not follow blocks (or any larger configurations used by the Census Bureau) so they just guess at the number of people in the split blocks, using an estimating formula.

They feel this is pretty accurate, but in courts that make a huge stink over a one person difference, this would likely become a big deal. For this reason, I would not consider this method to be a legally viable means of redistricting.

Some have proposed to solve this by going back and making the lines follow the Census blocks to eliminate the problem. It is true that this would eliminate the population issue, but then it also means that human-defined elements are introduced, which is precisely what the Splitline Method seeks to avoid.

Expensive To Implement

Another disadvantage not mentioned in the research is how costly something like this might be to implement. If the program does not follow political subdivisions, then theoretically a voting precinct might contain multiple districts. This would require multiple voting machines to handle the different ballots, which gets expensive!

Confusing to Voters

While straight lines look simple and appealing on paper, they do not translate into clear boundaries in practice. The Splitline Method admits to the possibility of a house being divided between two districts. That sounds a bit confusing. One complaint of the current system is how political subdivisions are sliced into fragments so numerous that it is impossible to identify the boundary from any standard map. It seems the Splitline Method would only magnify this problem.


People identify with the political subdivisions where they live. Governments have been formed around them since our country was originally founded. So then a viable solution to the current redistricting nightmare will keep in mind the history of where it all began and how it went wrong. Any districting system that so completely ignores the origins and foundation of this great land will not survive unless the system of rule itself is changed.


  1. You’re joking, right? We already have districts which vary by hundreds of Voters and You think a 1 Voter difference is not “legally viable”? You honestly think Whoever defines voting precincts cannot adjust them in such a way as to avoid the risk of one precinct straddling two districts? Or decide what to do if a house genuinely is divided between the two districts? I see the April 1st date on this post and I really hope this is a (bad) April Fool’s gag.

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