Scoring earthquake predictions or forecasts has been the subject of many posts here on this board. I suspect (and haven't yet researched) that geoF has used something we came up with in various discussions as the most effective (I believe Lowell was part of those discussions as well) - As I said - there are lots of conversations in the archives as to how it might be best to score quakes - These have always been very active threads. Lots of options available and everyone has an opinion about it. Its a tough subject.

Canie