# [EM] Fw: IBCM, Tideman, Schulze

Markus Schulze schulze at sol.physik.tu-berlin.de
Wed Jun 28 00:09:05 PDT 2000

```Dear Mike,

you wrote (27 Jun 2000):
> I've checked and D does seem to win in your example, with SD.
> I haven't checked Schulze in that example yet. I'd thought that
> I had a demonstration that SD would do like Schulze when the
> pair-defeat table has no equal entries. At this time I don't know
> whether or not your statement is correct, and so I can't claim
> that it isn't correct.

Via beat paths the pairwise defeats look as follows:

A:B=64:66
A:C=64:65
A:D=60:58
A:E=61:58
A:F=63:58
B:C=64:65
B:D=60:58
B:E=61:58
B:F=63:58
C:D=60:58
C:E=61:58
C:F=63:58
D:E=61:60
D:F=62:60
E:F=60:61

Therefore candidate C wins all pairwise defeats via beat paths.

******

You wrote (27 Jun 2000):
> But even if it is, SD still meets BC, and hasn't been shown to
> have any kind of problem when there are no identical entries in
> the pair-defeat table. Unless it does, it's still a very good
> candidate for a public proposal.

Suppose that candidate D is substituted with a set of clones
with D1 > D2 > D3 > D1. Suppose that all the pairwise defeats
between two clones are larger than 65:35. Then the SD winner of
my yesterday's example is changed from candidate D to candidate C.
Therefore SD violates independence from clones.

******

You wrote (27 Jun 2000):
> But of course till it's demonstrated that SD doesn't have a
> many-voters problem, I'll only propose Tideman instead.

Does that mean that you don't promote SSD any more? What is
the reason for that change in your opinion?

Markus Schulze
schulze at sol.physik.tu-berlin.de
schulze at math.tu-berlin.de
markusschulze at planet-interkom.de

```