I'm curious how the speed ratings men overcome track anomalies,such as......

Randwick,,,Good jockeys nurse their mounts to the top of the rise,then flog the fur off them until they greet the judge.

Cessnock (topical with me at the moment) Awful racetrack,the last three hundred metres is straight downhill.

I'm not knocking speed ratings,just wondering if courses like the above are eliminated from calculations,or the ratings from tracks with hills and dales are just incorporated into a general average??