If you're a visual thinker, you might enjoy these: http://zesty.ca/voting/voteline http://zesty.ca/voting/voteline http://zesty.ca/voting/sim http://zesty.ca/

If you're a visual thinker, you might enjoy these: http://zesty.ca/voting/voteline http://zesty.ca/voting/voteline http://zesty.ca/voting/sim http://zesty.ca/voting/sim Or, if you prefer logic: The intuition for "something strange could happen" is that IRV only uses some of the information on the ballots. Initially it uses just the top ranking on each ballot, and then at other points in the process, it might flip to using the second ranking on some of the ballots, and so on. There are these sudden trigger thresholds that cause big discontinuities in what gets counted—and that should feel weird. We have this pile of ballots that could all count for A or B; why should that decision depend on some unrelated other ballots? That's the mechanism by which ranking someone higher can cause them to lose. Only some of the second ranks on the ballots will get to count, and depending which ones get counted, we could get a totally different outcome. Suppose A, B, and C are all competitive in an election, with no one having an outright majority, but A has a little more support than B, who has a little more support than C. It could be the case that A is in a winning position because C supporters mostly like A as their second choice; when C gets eliminated first, those ballots count for A and A wins. But let's say B supporters all like C as their second choice, and you persuade some B supporters to switch to A. If enough of them switch away from B that B is eliminated first, then all those B supporters' ballots will count for C, and that can cause C to win. So by campaigning for A, you made A lose! The general idea is that if B and C are close, which way it tips can have a sweeping effect on whose second choices get counted, which can affect A. It should feel intuitively scary that a small shift in one part of the election can have a magnified effect on a different part. It's not good for systems to be unstable like that.