[EM] Sequential Pairwise is auto-deterrent

[Michael Ossipoff]

Just mentioning something that won’t be surprising, but I mention it
because it doesn’t stand out to you unless you’re looking for
auto-deterrent methods.

Say Sequential-Pairwise (SP) is voted as rankings instead of the usual
show-of-hands. After the voting, th rankings are used to count SP.

The comparison-order agenda is determined by Topcount or Approval.

(For Approval, your ranking is counted as approving every candidate you
rank, so truncate accordingly.)

Of course candidates with higher Topcount or Approval scores are higher on
the list, earlier in the comparison order.

Say you bury a candidate (“Buried”), perceiving hir a rival to your
favorite (“BF”).

Maybe you bury hir under lots of other candidates (“Buses”).

If BUried encounters a Bus, then your order-reverse Al makes that Bus more
likely to beat & eliminate Buried. The more Buses, the more her win
probably is reduced.

But if a Bus pairbeats Buried, then you’ve only replaced Buried with Bus.

Now instead of Buried maybe being eliminated with Buried surviving & maybe
winning, now Buried is replaced with Bus,  & so BF might instead be
eliminated with Bus surviving & winning.

You’ve worsened your expectation.

Your burial wasn’t a good idea.

Don’t do it.
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