classification calculation method -- time to make Fisher the default?

[David Relson]

Greg,

I've used all three algorithms.

During the pre-production evaluation period and for the first 3 weeks of 
production usage, I used the Graham algorithm.  Of course that far back, it 
was the only choice.

The switch to Robinson was made at the end of October for its improved 
ham/spam discrimination.

The switch to Robinson-Fisher was made at the beginning of December to take 
advantage of its ham/spam/unsure tristate results.  I'm very pleased with 
it.  A few spam that have avoided my spam and unsure folders since 
then.  Due to some database problems and a lexer defect (since corrected), 
those messages didn't have X-Bogosity header lines.  Excepting those 
hiccups, bogofilter and the Robinson-Fisher algorithm are doing a 
superlative job of classifying spam and keeping it away from my users.

I think it's time to change the default algorithm from Robinson to 
Fisher.  I have no reservations about supporting the change.

David