text: Side effects of First-past-the-post voting include a waste of votes due to vote splitting, a two-party system and political polarization due to electing candidates that do not support centrism. To understand why a race using First-past-the-post voting tends to favor less-centric candidates, consider a simple lab experiment where students in a class vote for their favorite marble. If five marbles are assigned names and are placed "up for election", and if three of them are green, one is red, and one is blue, then a green marble will rarely win the election. The reason for the green's lack of success is vote splitting. The three green marbles will split the votes of those who prefer green. In fact, in this analogy, the only way that a green marble is likely to win is if more than three-fifths of the voters prefer green. If the same number of people prefer green as those who prefer red and blue, that is to say, if one-third of the voters prefer green, one-third prefer blue, and one-third prefer red, then each green marble will only get one-ninth of the vote, if the green marbles each take same number of votes, while the red and blue marbles will each get one-third, putting the green marbles at a serious disadvantage. If the experiment is repeated with other colors, the color that is in the majority (if the majority is split among multiple choices) will still rarely win. In other words, from a purely mathematical perspective, a single-winner system tends to favor a winner that is different from the majority, if the majority runs multiple candidates, and if the minority group runs just one candidate. This minority rule success can also result if multiple winners are elected and voters cast multiple votes (Plurality block voting). But even if the majority is split among multiple candidates, proportionate results can still be produced if votes can be transferred, as under STV, or if multiple winners are elected and each voter has just one vote.