Back in the day I would make my life easy and just shove pre. However I study preflop recommendations that suggest to 3b 99 at this stack deph (to 4bb indeed, I did slightly more).
Villain PFR 48%, fold to 3b 50% small sample 100 hands.
PokerStars - 15/30 NL (2 max) - Holdem - 2 players
Hand converted by PokerTracker 4
SB: 18.07 BB
Hero (BB): 15.27 BB
SB posts SB 0.5 BB,
Hero posts BB 1 BB
Pre Flop: (pot: 1.5 BB) Hero has 9
9
SB raises to 2 BB,
Hero raises to 4.73 BB,
SB calls 2.73 BB
Flop: (9.47 BB, 2 players) A
3
4
Hero???