Choosing a size
3 of 4
Opposite hand
What size would I bet with the opposite hand?
In plain words
Think of the other kind of hand. With value, ask what a bluff would bet to fold him, and bet less. With a bluff, bet more than value would.
Ask it
When you pick a size on the river.
What it changes
Your value bets stay below the size where he folds, your bluffs go above it.