[BluffTHIS!]

pete,

Obvioulsy this or any principle could be misapplied in a discrete situation, especially if another important principle should take precedence (in the example I gave if you had a shorter stack and could bet yourself allin then that often would be correct because if someone doesn't have a big hand and something like KK is the only one that calls you, then you have cleaned up some additional outs when checking might have brought a certain turn card that kept another player in the pot).

And there are a lot of factors that go into determining whether you should bet or not besides just your hand strength in relation to the board. The more people in the pot then the more you should lean toward checking marginal hands and especially those with potential to make the nuts. And even HU the more tricky the opponent is, then the same thing. So if you know your opponent's tendencies very well, then you can make more bets and semi-bluffs with impunity if you think that they are more likely to fold. But it is a fine line and being overly aggressive in these spots can easily become a significant leak.