[SURBL-Discuss] Question about scoring in SA3

I've been very pleased with SURBL in SA3 and I'd like to increase the scores. However, I don't understand how the default scores like this work:

rules/50_scores.cf:score URIBL_AB_SURBL 0 2.007 0 0.417 rules/50_scores.cf:score URIBL_OB_SURBL 0 1.996 0 3.213 rules/50_scores.cf:score URIBL_PH_SURBL 0 0.839 0 2.000 rules/50_scores.cf:score URIBL_SC_SURBL 0 3.897 0 4.263 rules/50_scores.cf:score URIBL_WS_SURBL 0 0.539 0 1.462

I feel SA is being too conservative with the resource that SURBL provides. Can anyone give me their recommendations for my local configuration file for replacement scores that will be more effective?

And since I couldn't find it referenced, can anyone tell me what the four numbers after the score mean?

Regards, KAM