Why is a fifty-fifty situation so common in elections?

Question

I was just reading about the current elections in Sweden and that again reminded me of what I've been thinking of so often. Why is it so usual that political elections divide a country exactly into two? Why is such ratio such as 48:49 so common? I know there are places where democrasy works differently or due to corruption, there are rates with 90:10. But seriously, why is it fifty-fifty rather than, say, 20:75? Thanks in advance!

Answer 1

Because most politicians want to win power. So they try to do/say/convince/compromise enough to get a majority. Once they have a majority, they don't need to do any more compromising.