I just felt this hand illustrated how a passive approach can cost you so much EV.

Hand History:

Texas Hold'em $4-$4 NL (Real Money), #1,332,499,976
Table Venice, 4 Dec 2006 8:22 PM ET
Seat 1: WEAK PASSIVE PLAYER ($415.45 in chips)
Seat 2: Lovely55 ($205.20 in chips)
Seat 6: joker400 ($165.80 in chips)
Seat 9: Robuschi ($142.50 in chips)
Seat 10: Wota ($194.50 in chips)
ANTES/BLINDS
Wota posts blind ($2), Mr Passive posts blind ($4).

PRE-FLOP
Lovely55 folds, joker400 folds, Robuschi folds, Wota bets $16, MR PASSIVE calls $14 (Mistake no.1, if he thinks AJ is not good he should fold if he thinks it is and makes this $48 I would fold).

FLOP [board cards 7H,JavaScript,6C ]
Wota bets $22, Mr Passive flat calls with top pair $22 (mistake no.2 - is he slowplaying 1 pair/does he not know where he is? Again if he makes this $70 I struggle to call. As it happens I may push all in but thats another matter )

TURN [board cards 7H,JavaScript,6C,10H ]
Wota checks, Mr Passive bets $15 (into $76), Wota calls $15. (mistake no.3 - Just why would anybody make this ridiculous bet?)

RIVER [board cards 7H,JavaScript,6C,10H,3C ]
Wota bets $66, Mr Passive calls $66. (Mistake no.4 - If top pair is good enough to call $66 here, it should have been good enough to bet $66 1 card ago and I would have folded.)

SHOWDOWN
Wota shows [ 4H,5S ]
nano25 mucks cards [ AS,JH ]
Wota wins $239.
SUMMARY
Dealer: Robuschi
Pot: $242, (including rake: $3)
nano25, loses $121
Lovely55, loses $0
joker400, loses $0
Robuschi, loses $0
Wota, bets $121, collects $239, net $118

He had 2-3 opportunities where he could of won this pot but he let me get cheaply to a lucky river and ended up paying.

ahhh, the loose passives.. gotta love those guys

Very tough question to answer how I would play against myself. I would probably not flat call the $70 raise ever. If I did he would certainly be beaten with AJ before that turn but does he know that?

4 handed table in a heads up pot with no reads its not easy to get away from TPTK I don't think.