Systems of proportional representation (PR) are known to produce centrifugal incentives that encourage especially small parties to take extreme policy positions. This research project investigates the political forces that provoke such polarising tendencies and explores the potential of the Borda score to allocate seats under a system of proportional representation with the aim of countering party system polarisation. Borda voting is a choice rule from the class of preferential voting systems that takes the complete preference ordering of voters into account. It is known to be immune against many voting paradoxes and beneficial for consensus-seeking candidates. Relying on formal theory, computational methods, survey experiments, and empirical analyses, the project will analyse the properties and incentives that arise in PR systems if seats are allocated in proportion to the Borda score rather than in proportion to first ranks. Based on the results generated by the project, it will be possible to evaluate whether a Borda-based PR rule is better equipped to counter polarising party strategies while maintaining many of the positive aspects of proportional electoral systems.