I added logging to the Validate Trackback LifeType plugin. I was curious about how many trackbacks were caught by the ip dnsbl checks, url dnsbl checks, checking to see if there was a resulting trackback ping url, or the Bayesian filter.
From December 2nd to today:
5808 trackbacks were stopped because the resulting pages do not have a trackback ping url.
2830 trackbacks were stopped becuase the ip address was listed in a dns blacklist
16 trackbacks were stopped because the domain of the trackback url was listed in a dns blacklist
It looks like all of the trackbacks were caught before the Bayesian filter had to be run.