This is a subject which gets a wide range of views from racing people. Whether you can compare the champions from one era to another. For example , Phar Lap was the champion of the 1930's. Bernborough was the champion of the 1940's and Tulloch was the champion of the 1950's. There were numerous candidates in the 1960's with Kingston Town the champion of the late 1970's and early 1980's. Since then we have had many top horses and many pretenders. The qualities which these special horses possess are very rare-win against all opposition, under all conditions and at all distances, regularly with crippling weights.
In my opinion it is almost impossible to effectively compare one champion as "better" than another because so much has changed over the last 70-80 years.
Look at human performance over this period and how things have changed.
For example, the swimmer, Johnny Weismuller, won a swag of Olympic medals in the 1920's and was proclaimed "the greatest swimmer" in history. He later starred as "Tarzan" in a series of Hollywood films.
However, today, with better nutrition, better health and advances in science and medicine he would be "lapped" by a 12year-old girl. Therefore, to compare racehorses from era to era is a very hard task and they should be acclaimed as the best of their era and it should be left at that.
Any opinions out there and any nominations for "greatest horse(s) ever?
I look forward to opinions on this matter with a great deal of interest.

Cheers