Facts is how many assertions this source filed; Won is how many judged events it was the assertion in force for. A source with many facts and few wins is one that is being outranked, which is worth knowing before concluding it is wired correctly.
Source is the asserter these two counts are for — chargeoff, dispute, case, refund, review or sample. There is one entry per source that either filed in the window or won in it, in precedence order, strongest first. A source no longer in the vocabulary still has rows and is reported after the known ones rather than dropped out of a total that is supposed to add up.
Won is how many JUDGED events this source's assertion was the one IN FORCE for, at that event's own as-of — it beat every other visible claim under the precedence rule. Summed over the sources it is Judged. Read against Facts it is the ratio that matters: many filed and few won is a source being outranked, not a source that is broken, and one source winning nearly everything is a plane that looks labelled because one noisy filer dominates it.