Let's postulate 1 million voters, 451k registered R voters, 450k registered D voters and 99k registered I voters.
Let's postulate that each 1st place vote is 3 points, each 2nd place vote is 2 points and 3rd place gets 1 point.
OBVIOUSLY the registered R voters are going to put Candidate R in 1st place, Candidate I in 2nd place and Candidate D in last place.
OBVIOUSLY the registered D voters are going to put Candidate D in 1st place, Candidate I in 2nd place and Candidate R in last place.
And the registered I voters put Candidate I in 1st place, Candidate D in 2nd place and Candidate R in 3rd place.

In the 1st round of voting - in which only 1st place votes are counted - Candidate R gets 1353k points, Candidate D gets 1350k points and Candidate I gets 902k points.

So Candidate R WHO GOT THE MOST FIRST PLACE VOTES and THEREFORE WOULD HAVE WON IN A NORMAL ELECTION but DOESN'T outright win here because Candidate R does not have a majority.

So we throw away the last place candidate's votes and distribute that candidate's 2nd place choices to the remaining candidates.

So now Candidate R has 1353k + 99k = 1452k points. 

And Candidate D has 1353 + 198k = 1551k points. And wins. Despite the fact that Candidate R would have won in a normal election.

Yeah, that makes a lot of sense.  NOT.

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