5/45 weird stack sizes after CB
 

PokerStars No-Limit Hold'em Tourney, Big Blind is t50 (8 handed) internettexasholdem.com

MP2 (t1510)
Hero (t5745)
Button (t2675)
SB (t875)
BB (t2005)
UTG (t1660)
UTG+1 (t1690)
MP1 (t1240)

Preflop: Hero is CO with Q[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, MP1 calls t50, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to t200</font>, Button calls t200, <font color="#666666">2 folds</font>, MP1 calls t150.

Flop: (t675) 5[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
MP1 checks, <font color="#CC3333">Hero bets t500</font>, Button folds, MP1 calls t500.

Turn: (t1675) J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
MP1 checks, <font color="#CC3333">Hero ???</font>

He has 540 left.

Reasons for checking: free card vs overpair is so juicy, and I don't want to just throw in more money when I have no pair and seemingly little FE.

Reasons for betting: if he has me beat, getting it in with 6-10 outs is not that awful with the pot size. I could also easily have the best hand (this is a 5/45, remember), and if so, getting called or not is fine, but checking through is kinda gross.

Also, should I have played differently earlier in the hand to avoid this? Is the CB on the flop good in general?