[Kirkrrr]

From some of the other posts I've read I think a good chunk of it has been covered, but I'll give you these simple scenarios:

You're in an early position with a marginal hand against 3 opponents, and decide to bet. First to you folds, next one raises, and the 3rd player re-raises. You, obviously, fold. Now suppose you're with the same hand but in the last position. First player now checks, second bets, third raises, and you quietly muck your marginal hand without ever having made that first bet and wasted your chips.

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If you consider being checked to on the button as reliable information, you are subject to a check/call check/raise from someone who has flopped the nuts.

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Yes, you are, but the number of players who do that often is not that great, first of all. Secondly, again, if you are last to act and it's bet/call on a non draw-heavy board, you're done with the hand most of the time without wasting any more chips. If you're OUT OF POSITION and decide to take a stab at the pot and get called (but not raised) on a draw-heavy board now you have a difficult decision - fire again on the turn, or save it? If you decide not to, can you try to take it down again on the river? With position, a good opponent can slowplay a lot more effectively since he knows he'll have the last action so he can always value bet if checked to twice, or raise if bet into, and has less fear of getting nothing else out of the hand.

Hope this helps. It's way too early for 2+2 so I'm not sure how much sense, if any, I made.

Kirk