Been thinking about free showdown raises

[kidcolin]

So here's the situation. You're playing against your typical loose passive guy. He limps, you raise. Flop is good. You hit TPTK or TPGK. Now he bets/3-bets you. You know your toast, but you have outs, and you plan on making a crappy river call UI because you don't have much history on the guy. Against passives who usually fear monsters, should we be popping some favorable turns? Or wait to pop a favorable river?

Here's an example from today that got me thinking about it. Villian is something like 50/5/0.8 or something like that. MP sucked too. Hero is Larry Bird.

Party Poker 5.00/10.00 Hold'em <font color="#0000FF">(6 handed)</font> link

Preflop: Larry Bird is CO with Q[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/spade.gif[/img].
UTG calls, MP calls, <font color="#CC3333">Larry Bird raises</font>, <font color="#666666">1 folds</font>, SB calls, BB calls, UTG calls, MP calls.

Flop: (10.00 SB) A[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, BB checks, <font color="#CC3333">UTG bets</font>, MP calls, <font color="#CC3333">Larry Bird raises</font>, SB folds, BB folds, <font color="#CC3333">UTG 3-bets</font>, MP calls, Larry Bird calls.

Turn: (9.50 BB) K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">UTG bets</font>, MP calls, Larry Bird ?


Now I'm thinking, "he probably has A4 or AJ, maybe 44. This board is scary as hell against my range. He's probably not 3-betting ever, since I could have AA, KK, AK, AJ, or even QTs. So do you think a raise is better than a call here? How does MP play into all of this? I'll give my thoughts after some discussion gets going.