# [EM] Strategy thoughts

Dave Ketchum davek at clarityconnect.com
Tue Dec 8 20:27:09 PST 2009

```On Dec 5, 2009, at 7:41 PM, Dave Ketchum wrote  on:  Election Goals &
Methods - a review:

Here I explore some possibilities based on using margins.  Assuming
polling has given perfect knowledge as to the voting without strategy,
what change might a strategist propose for the one group of voters
that hears strategy gimmicks.
>
> 45A
5A,B - these 5 voters add in B as second choice.  Effect is  31B
to 29 C and B winning.
> 11B
3B,A - effect is 48A to 44C and B winning (3 vote margin is less
than this 4 vote margin).
> 15B,C
3B - effect is 45A to 41C and B winning.
> 29C,B
6C,A - effect is 51A to 49B and A winning (hard to sell, since C
wins without strategy).
>
> The pairwise defeats are as follows:
> B beats A, 55 to 45 (55 winning votes, a margin of 10 votes)
> A beats C, 45 to 44 (45 winning votes, a margin of 1 vote)
> C beats B, 29 to 26 (29 winning votes, a margin of 3 votes)
>
> Using the winning votes definition of defeat strength, the defeat of
> B by C is the weakest, and the defeat of A by B is the strongest.
> Using the margins definition of defeat strength, the defeat of C by
> A is the weakest, and the defeat of A by B is the strongest.
> Using winning votes as the definition of defeat strength, candidate
> B would win under minimax, Ranked Pairs and the Schulze method, but,
> using margins as the definition of defeat strength, candidate C
> would win in the same methods.
> If all voters give complete rankings of the candidates, then winning
> votes and margins will always produce the same result. The
> difference between them can only come into play when some voters
> declare equal preferences amongst candidates, as occurs implicitly
> if they do not rank all candidates, as in the example above.
>
> Dave Ketchum
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