It turns out (but it's not at all obvious) that the number of times a voter is critical in winning coalitions is equal to the number of times he/she is critical in blocking coalitions.
But isnt the power index for the banzhaf supposed to be an integer and not a fraction? For the Shapley-Shubik index it is supposed to be a fraction, but for banzhaf isnt it supposed to be an integer?
+narechoke513 There's no rule that says it has to be an integer or a fraction. I think power indices are best expressed as fractions so that you can tell right away what fraction of the total power each voter has.