Why?, Dont think it's got anything to do with the track itself CP, although it is known to favour front runners, other than that there are 60+ trainers operating out of there & it is close to Perth, which makes it the best provincial training area in the state.

Therefore imo winners at that track that are then sent out to non-metro races at their next start away from Bunbury may often be meeting slightly inferior opposition despite the fact they are probably moving up in class. If they are running again at Bunbury, well they are in form & having won their last start there, odds are they are front running types. & the non-fav filter helps add value to the system.