So when do we bet for protection?
This is a cross between value-betting and bluffing – usually referred to as a type of thin value bet. You bet in a situation where you don’t necessarily expect to get called by worse very often, but your opponent’s range still has a decent amount of equity vs your hand. As a result – your opponent folding is considered a good outcome despite your bet being for “value”.
Consider this example:
Effective stacks are 100bb. You are in the CO and open raise to 3bb with 44 . SB calls. BB folds.
The flop is k73. BB checks. Hero bets 4bb into the 7bb pot.
(By betting hero is “protecting” his hand from anything with 2 overcards. Hero does not necessarily expect a call from these hands (although it will happen sometimes) – but he doesn’t want to check back and allow them free chances to hit. Occasionally villain will call with worse like a 3x or an OOP float like AJ, but occasionally he will also fold better. Some villains will muck better pocket pairs and 7x. It’s not really correct to refer to this play as a pure “bluff” however, because hero still expects to have the best hand a decent amount on such a dry board.