[betterbettor]

PowerRangers, the problem with just c/c the river is you lose value vs worse hands that would call a small bet but just check behind, and you still pay off the better hands for possibly more than the price of your block bet.

I think Bazooka, Unknown Soldier and several others have the right idea. I'm not sure if the 50% is the right number though, it depends on the opponent and pot size.

Often a block bet will be a two way bet, in value/bluff territory. Some worse hands will call, some better hands will call but not raise(you set your own price), and only good hands and bluffs will raise and you can usually comfortable fold.

Like Thac pointed out, most block opportunities come on a scary board, where the opponent has a hard time raising without the hand the board helps. It helps if the actions leading up to the river make it possible that you could have that hand also. It's important to have a feeling how your opponent will react to a blocker. Thac and others who fake block to induce a bluff, you may want to note those players(if regulars and they pay attention). Once you bet 1/3 pot on river with near nuts to eek out value or induce a bluff, your block bets should now become more effective(meta) vs aware opponents.

Just my humble opinion, and I struggle like most with thin block bets.