Stars 55 regular - BB special

[cha59]

Villain appears to be paying attention. He is a winning player on sharkscope and has solid PT numbers.

PokerStars Tournament, Big Blind is t150 (6 handed) Converter on pregopoker.com

UTG (t2594)
UTG+1 (t2900)
CO (t1888)
Button (t2193)
SB (t2565)
Hero (t1360)

Preflop: Hero is in BB with J[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/heart.gif[/img]
<font color="gray">UTG folds</font>, UTG+1 calls t150, <font color="gray">CO folds</font>, <font color="gray">Button folds</font>, <font color="gray">SB folds</font>, Hero checks

Flop: (t375) 4[img]/images/graemlins/club.gif[/img] 4[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/spade.gif[/img] (2 players)
Hero - what's the plan?

I should add that he probably noticed that I have played very tight and I have shown down only premium hands to this point. He most likely noticed a big pot I lost in a set over set hand. I doubled back up with AK shortly after that loss. This is affecting my thinking.