Never Do This!!

I don't have much time to post today, but I'd just like to talk about something that I have seen happen a few times in poker in my life. You should NEVER fold the river if all you are last to act and it is checked to you. This might seem obvious, but some players when caught in a bluff will just fold their cards assuming they are beat. You have nothing to lose by showing down your hand at this point, it doesn't cost you anything. Some players might say that they don't want the other player to know how they played their bluff. I argue that if you are a capable player you should mix up your play enough that it doesn't matter if he knew how you played that bluff, as you should have many many different types of bluffs in your arsenal. Here is an example of a hand that came up between me and a great player (I edited out his name).

Green Plastic is at seat 1 with $8524.
Player X is at seat 7 with $15811.
Player X posts the small blind of $25.
Green Plastic posts the big blind of $50.
Green Plastic: 9c 7c
Pre-flop: Player X calls. Green Plastic raises to $150. Player X calls.
Flop (board: 4d Th 6c):Green Plastic bets $300. Player X calls.
Turn (board: 4d Th 6c Ac):Green Plastic checks. Player X bets $900. Green Plastic calls.
River (board: 4d Th 6c Ac 5h):Green Plastic checks. Player X folds.
$.50 is raked from a pot of $2700. Green Plastic wins $2699.50.

Now, about this hand. I won the 2700 pot with 97, no pair. I usually would either fold or raise this turn here because all i had was a flush draw and gutshot straight draw, but this player had been firing out big bets on the river all day on me (when he was pretty sure I couldn't call) and i wanted to have a chance to make a big hand and checkraise him once. I had a lot of chips on the table so I figured if i got lucky and hit one of my 12 outs, I could possibly get all in for a huge pot. Also, even if I missed (and he checked) I wanted him to know that I am willing to "gamble" and could hold and/or check any two cards at the end. This would make him less likely to keep stealing pots on the river against me, as I suspected he was doing. In the end he was probably bluffing with no pair, or a small pair, and decided he didn't want me to see his hand. The truth is, a good player (me, I think) is smart enough to know why a person would fold a hand when it is checked to them. So he didn't get a chance to win the pot with whatever he had, AND i know that he was bluffing there. Interesting hand, comments?