I assumed it was 10+pts, and 7 Spade suit -- am I correct?
This question isn't going to be answerable unless you give more details about the bidding system that you were using.– bwarnerMay 1, 2013 at 19:03
@bwarner: edited my answer...– user5185May 1, 2013 at 19:09
What was the vulnerability? Who was dealer? Was either partnership playing a strong club system? The answer to all of these questions will weigh in on the fine details of the answer.– Forget I was ever hereMay 2, 2013 at 1:20
A jump overcall is pre-emptive and generally shows the same values as a pre-emptive opening bid.
So in this case 3S could show as little as 6 HCP with 7 spades.