I get pleasing results with this formula:
sub tension {
my ($hi, $lo) = @_;
$lo or return 0;
2 * log($lo)/log($hi + .1);
}
where
$hi is the higher number of votes (whichever direction) and
$lo is the number of votes in the other direction. Any result above 1 represents an interesting amount of tension, IMO. Here's a table of results:
Hi # | Lo # | Tension |
3 | 3 | 1.9420 |
8 | 3 | 1.0504 |
8 | 8 | 1.9881 |
20 | 3 | 0.7322 |
20 | 8 | 1.3860 |
20 | 20 | 1.9967 |
50 | 3 | 0.5614 |
50 | 8 | 1.0626 |
50 | 20 | 1.5308 |
50 | 50 | 1.9990 |
90 | 3 | 0.4882 |
90 | 8 | 0.9240 |
90 | 20 | 1.3312 |
90 | 50 | 1.7383 |
90 | 90 | 1.9995 |
Caution: Contents may have been coded under pressure.