The standard sizing for a 4bet at NL5 and higher is 2.5x your opponent’s 3bet.
This allows you to make a raise small enough to possibly still get away from your hand. But since we always have a nut range anyways, this is really just an illusion to induce action. There is no need to put in a massive 4bet since a normal sized one represents such a large portion of a stack already.
At NL2, I would make it a little bit more, maybe 3x just because they will call it. Or sometimes I will just go all in as that looks bluffy to them. At both limits I will certainly adjust my sizing upwards a little bit if the stacks are really deep. On the flip side, if the stacks are considerably less than 100bb I will probably just click it back or shove.
But in general this stuff isn’t really that big of a deal since you shouldn’t be making very many 4bets at the micros in the first place.
All stacks below are 100bb deep.
Example: Blinds are 1c/2c. In LP you have,
A Nit opens to 8c from MP and you make it 24c. He 4bets to 60c.
You should fold.
Example: Blinds are 1c/2c.
In LP you have,
An SLP opens to 6c from MP and you make it 36c. He min 4bets to 66c.
You should go all in.
Example: Blinds are 2c/5c.
In LP you have,
You raise it to 20c.
A TAG (with a 5% 3bet) makes it 60c from the SB.
You should 4bet to $1.50 and call a shove.
