50NL Pocket 99's on CO.....correct line? What to bet on turn?

[BIGFISH72]

OK, I've not been having the best of it of late and so have decided to play less tables, read more, post more and comment when I feel I can.

Thanks for any useful comments.

Villain is 21 /8 /0.3

My question is this. How much is correct to bet on the turn after villain checks to me? Bearing in mind he had $21 left before I make my turn bet?


PokerStars No-Limit Hold'em, $0.50 BB (8 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP1 ($63.55)
MP2 ($28.95)
Hero ($122)
Button ($46.20)
SB ($9.50)
BB ($27.25)
UTG ($45.55)
UTG+1 ($15.85)

Preflop: Hero is CO with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">MP2 raises to $2</font>, Hero calls $2, Button calls $2, <font color="#666666">2 folds</font>.

Flop: ($6.75) T[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">MP2 bets $2</font>, <font color="#CC3333">Hero raises to $6</font>, Button folds, MP2 calls $4.

Turn: ($18.75) 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
MP2 checks, <font color="#CC3333">Hero bets ????