What does SSI stand for?

I see this on Sporting post race cards, what is SSI?:S

i think its sired south of the line, so possibl;y sired in the northern hemisphere but to southern hemisphere time

Ud... its something to do with stakes earned index.... email sporting post(tu)

oops, i thought you meant SSL and not SS(eye)

SSI is Standard Starts Index.
Invented in the USA .

It is total earnings of a horse divided by the average earnings of all horses of the same age and sex.
If the horse is average it will have an SSI of 1.00

A higher SSI normally indicates a higher quality horse (takes fewer starts to earn more).
Some people use it as a help to punt.
It does have some merit, otherwise I would have canned it long ago.
Every race also has a race SSI, which gives an idea of the quality of the race.

Thanks Karel. Would you say it is more usefull than earnings per run?

It is earnings per run, but refined (to bring it in context with age & sex)