It's a kind of optimised variant of the 'runoff voting', where the election is rerun with one fewer candidate if noone gets a majority. That's where the name co

It's a kind of optimised variant of the 'runoff voting', where the election is rerun with one fewer candidate if noone gets a majority. That's where the name comes from. In these parts (the UK) the same system is known as the Alternative Vote (AV) which is just as meaningless a name. But in defence of my fellow political scientists, there are a lot of different voting systems, many of which have alternatives, rankings, and runoffs, so unambiguous and useful names are hard to find.