"According to David Sklansky, Game theory shows that a player should bluff a percentage of the time equal to his opponent's pot odds
to call the bluff. For example, in the final betting round, if the pot is $30 and a player is contemplating a $30 bet (which will give his opponent 2-to-1 pot odds
for the call), the player should bluff half as often as he would bet for value (one out of three times)." - from wikipedia
Is this to say that every situation where you can't bluff (because it would be doing it too often) and you can't value bet either (because you don't have a hand), you're supposed to check/fold?