[gergery]

Very opponent dependent.

99 is dealt 1 way as there are two out there.
J9 is dealt 2 ways
A9 is dealt 6 ways

You have to figure he would play that way with either 99 or J9, so its twice as likely you are beating him, and if he'd play that way with A9 then you are very likely ahead.

After you raise and he reraises, then you need to evaluate how likely it is he'd play that way with A9 - not very likely, or J9 still likely but somewhat less so.

So I'd have raised him at least once and more if he was bad.

-greg