An Interesting No Limit Question

[David Sklansky]

I could've posted this question on our Poker Theory or No Limit forums but since this forum is now attracting some bigshots that don't post elsewhere, I thought I'd pose it here.

It is an elementary precept of limit poker that you should not bet a decent hand, head up, on the river, if you know you won't get called unless you are beaten (unless of course there is some chance that bet will make an even better hand fold).

But there is an exception to this rule in No Limit. There is a situation, not all that rare, where it is right to bet on the river even though there is no chance of getting a better hand to fold OR getting a worse hand to call. In other words if they call your bet you will lose. Actually there are two situations. One is when you feel it is worth risking a bet to keep from having to show your hand. But that is not what I am speaking of here. Littleshots are free to answer as well.