If you read closely I said "The majority of ISG events are on surfaces other than hardcourt, too." (or grass, or indoor)"
When writing that, why should I have bothered to include "hardcourt" and "indoor" in this sentence if I didn't want to differentiate between outdoor hardcourt and indoor hardcourt.
But just for you, I will write "outdoor hardcourt" next time to prevent this misunderstanding although I have already indicated that with my indoor category.
"Indoor" is indoor, no matter if carpet of hardcourt.