[EM] IRV Failures

[Daniel Bishop]

Eric Gorr wrote:

> In a recent conversation with an IRV supporter I asked the question:
>
>  What cases would you accept as failure of IRV?
>
> They answered:
>
>  Where the general public (or a significant fraction of it) failed to
>  accept the results as legitimate, or at least beyond question.  The
>  2000 and 2004 Presidential elections are examples of failed elections.
>  San Franciso's election was heralded as a success.
>
> They also believe that IRV has never failed to produce a fully 
> satisfactory result. Can anyone provide evidence to the contrary?

It's going to be hard to find an example.  And here's why:

Consider the five-candidate election:

   Total Votes: 397
   Voted needed to win: 199

   Round #1:

   A: 100
   B: 86
   C: 75
   D: 73
   E: 63 -- eliminated

   Round #2:
 
   A: 100
   B: 86
   C: 138
   D: 73 -- eliminated

   Round #3:
 
   A: 100 -- eliminated
   B: 159
   C: 138

   Round #4:

   B: 259 -- ELECTED 
   C: 138
 
B is, of course, the wrong choice, because A is the Condorcet winner.  
But try to prove it from the IRV vote counts.