[EM] Weak FBC and equal-ranking-allowed IRV (was "Kevin, you wrote.."etc.)

[Chris Benham]

Kevin,
I  was surprised to see  you recently write (Fri.Oct.17)

"The point of allowing equal ranking in IRV, is to make it always safe to vote
without order reversal."

because equal-ranking-allowed whole votes IRV doesn't really comply with weak Favourite
Betrayal Criterion.

45:R
20:C>R
08:L=C
27:L>C

This gives the tallies R:45  C:28  L:35. Centre is eliminated and then Right wins.
Assuming that the eight L=C voters' sincere favourite is Left (and they have followed your
advice that it is "always safe to vote without order reversal"), then they could have gained
a result they prefer by order reversal(down-ranking their sincere favourite).

45:R
20:C>R
08:C>L
27:L>C

Now the tallies are R:45  C:28  L:27. Left is eliminated and then Centre wins.
This example also applies to the two close relatives, RWE (Runoff Without Elimination)
and GIR (Gradual Information Runoff).
For me the main point of allowing equal ranking in any method is to avoid the result 
being maybe determined by the coin tosses of voters. I agree that the whole votes version
is better because it does greatly ameliorate the "favourite betrayal" problem.

Chris Benham