[IceKing]

OK. One simple example. Three players in the pot. Player A checks, player B checks because he cant bluff against two players, C checks too and shows a winning hand. Now if player A folds, its more easier to player B to bet, because he knows for sure that player A isnt going to call/raise. Now player C is in a bad spot. Player C decides not to call. What happend? Player C lost a pot he would have won, if Player A had checked instead of folding.