I planned to move onto proportional voting systems, But IRV keeps coming up in comments for single-winner. I do not recommend IRV and frankly, Bucklin, another system which Score-Voting outperforms is better than IRV.

IRV started in Australia over an hundred years ago. The National Party and the Liberal Party (2 Libertarian-Like parties) kept splitting the vote, thus causing the Labor Party to win. The 1st of them to fail transfers its votes to the other, giving it a chance to win. The beauty of this system is that it keeps 4th parties and independents from winning:

On the right, members of minor parties, list their candidate as number 1 and, as a backup, with National or Liberal as number 2 and the other as number 3. On the left, members of minor parties list their party as number 1 and Labor as number 2, just in case. The elimination of each minor candidate transfers more votes to Labor. Eventually, Either National, Liberal, or Labor wins.

FairVote.Org pushes IRV in the United States of America as letting 3rd Parties and independents win, and preventing spoilers. IRV prevents spoilers (the votes for Nader would have gone to Gore, thus letting Gore win in 2000), but I RV does not let 3rd Parties and independents win. Instead, every elimination pushes the Republicrats and Democans closer to victory.

FairVote.Org could have pushed American IRV (Bucklin) but did not:

In the Progressive Era, voters noticed that vote-splitting makes voting for anything other than the lesser of 2 evils, is a vote for the greater of 2 evils —— ¡Trump arserapes us all because a bunch of stupid Bernie-Or-Busters got butthurt over their prefered candidate loosing the primary and rather than voting for the winner who matriculated ⅔rds of the planks from his platform into hers, voted 3rd party and independent! —— under plurality. Bucklin came up with an American System of instant runoffs solving this problem:

In Bucklin, The voters use a ranked ballot. If no candidate gets over 50% of the votes, the votes of the next lower rank are added to the total until 1 or more candidates gets over 50%. If more than 1 candidate gets over 50%, the candidate with the most votes wins.

¡Bucklin worked! The Democan and Republicrats joined forces to kill Bucklin because it broke their duopoly. By the 1st World War, Bucklin was pretty much dead, with some municipalities using it into the 1920s.

Rather than using Australian IRV, which almost never allows 3rd parties and independents to win, ¿why did not FarVote.Org throw its support after American IRV (Bucklin), which allows 3rd parties and independents to win?

In computer-simulations, Australian IRV and Plurality are the worst, Bucklin (American IRV) and Borda-Count are better, Approval is better still, Condorcet is yet better, and Score-Voting is best. It is interesting that FairVote.Org fights Approval voting, a system which works on all voting equipment known to the author and superior to Australian IRV, tooth and Nail.