Example where IRV leads to worse election result than plain plurality voting

#voters their vote
30 A>B>C>D
26 B>A>C>D
24 C>A>B>D
10 D>B>A>C
10 D>C>A>B

In this 100-voter 4-candidate election by Toby Pereira (candidates named A,B,C,D) the winner under IRV (instant runoff voting) is B.

Round #1: A(30) - B(26) - C(24) - D(20) eliminated
Round #2: A(30) eliminated - B(36) - C(34)
Round #3: B(66) - C(34) eliminated
Winner: B.

However A is the winner under plain plurality voting, with 30 votes, beating B(26), C(24), and D(20). Also A beats every rival pairwise by convincing margins, e.g.

A beats B 64-36 (meaning 66 voters rank A above B versus only 34 who rank B above A); A beats C 66-34; A beats D 80-20.

A also wins under the Borda count system, with score 210 versus B(182), C(148), and D(60).

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