Borders of Election Districts
Not the overall majorities, but rather more many subtleties in the regulation of an election contribute to the final distribution of seats in a parliament. It is not seldom, that legal possibilities are stretched and exploited as far as possible by political interest groups. For example, when from each constituency only one representative with the majority of votes can achieve a seat in parliament, then how the border of the election district is fixed can be of crucial importance. The exploitation of this effect (so-called Gerrymandering) can sometimes create interesting results, as the picture below shows.
In the animation, one can see how even a seemingly simple and fair rule, such as "Each voter goes to the nearest polling station", can lead to a distribution of seats, which does not reflect the majorities amongst the population. One can change the positions of the polling stations (yellow). Most of the time, it is possible to achieve a majority for "Blue", even though this party only receives approximately 40% of the votes.