[EM] proper Borda implementation

[Bart Ingles]

Jeffrey O'Neill wrote:
> 
> I'm not sure of the best way to implement Borda with ballots that don't 
> rank all the candidates.  Suppose that 4 candidates are running.  With a 
> ballot like:
>     A B C D
> A gets 4 points, B gets 3 points and so on.  But what about a ballot like
>     A B
> A and B should be treated as above, but what about C and D?  I see two 
> options:
 >
> (1) C and D each get nothing.
> (2) C and D each get 1.5 points (average of leftover points).
> 
> Any thoughts as to which is better?

I would say (1) is the better alternative, but then I'm not exactly a 
Borda advocate.

I believe the classic interpretations are either (2), or else to simply 
disqualify incomplete ballots.