Got me beat too, Kiwi. Make em all set weights or WFA and don't worry about it. Of course,even that doesnt work correctly (since 50-1 shots still get up in "classics" like the SA Derby 9 days back) Or, more fairly, every horse in every race carries a set percentage of it's bodyweight (say 10 or 15) ,meaning that we would then see which really is "pound for pound" the best horse!!