i found a good site for dosage explanation for those like me that still get confused,lol.
I made some notes about the basic ideas:
Brilliant - Intermediate - Classic - Solid - Professional
High Dosage Index - a tendency to perform best over shorter distances, while low numbers - preference for longer races.
furlongs = 4…5…6…7…
CD Scale = +2 (brilliant)
furlongs = 8…9…10…11.
CD Scale = +1 (intermediate)
furlongs = …12…13…14
CD Scale = 0 (classic)
furlongs = …15…16…17…
CD Scale = -1 (solid)
furlongs = …15…16…17… 18+
CD Scale = -2 (professional)
It’s a really good sight I took notes too! 
I found it through pedigree query.