Banzhaf power index

A voter's power is measured as the fraction of all swing votes that he could cast.

There are 12 total swing votes, so by the Banzhaf index, power is divided thus:

The Banzhaf power index would be a mathematical representation of how likely a single state would be able to swing the vote.

However, if New York is replaced by Georgia, with only 16 electoral votes, the situation changes dramatically.

What is known today as the Banzhaf power index was originally introduced by Lionel Penrose in 1946[3] and went largely forgotten.

Banzhaf wanted to prove objectively that the Nassau County board's voting system was unfair.