# Giving a short stacked opponent a perfect all-in vs forcing them to over-commit

I just finished Every Hand Revealed by Gus Hansen and in it he is talking about a short-stacked opponent and says:

I should probably watch out so I don't give him too many perfect all-in moves before the flop. It is imperative to manipulate the size of my pre-flop raises so that [he] either has to over-commit his chip stack for a small gain or else he will simply have to see a flop.

Can someone explain the math behind this type of move and how to calculate the cut off bet between giving your short stacked opponent a perfect all-in and forcing them to over-commit?

Edit: March 6th, 2012

The following example (adapted from the book) is what alerts Hansen to make the above quoted statement.

``````Table is 7 handed
Blinds and Antes: 15/30/5
Seat 1: Gus Hansen with 4,800
BB: Villain with 450
``````

The `Button` opens with a raise (amount not specified) and `Villain` pushes all-in. I'm assuming Hansen's concern is for when he is on the `Button` and `Villain` is now in `Seat 4`. How much should he raise to make moving all-in a bad move for `Villain`?

• Gus took an entire book to explain that it is not a precise science. You have to make guesses, judgements, and decisions.
Mar 6 '12 at 21:49

If your opponent has `10 000 in chips` and the blinds are `200/400` your normal raise would be something around `1000 - 1350` which means that it's with the blinds something around `20% of your opponent's stack`. He can go All in now and win your bet + blinds which is not much but can lose a lot (everything) if he gets called by you (or even reraised all in). If he for example would have only `5 000 in chips` now this becomes almost `40%` which means he is getting almost `2.5:1 odds` for his money. If he has any kind of decent hand (any Group 1-3 hand from sklanksy chart) he can go all in because it's profitable for him.

The bottom line is. If your raise will be a bigger portion of your opponents stack he will be priced in to go all in because he can win a lot of chips with a decent hand. If the bet is still too small to give him the right odds for an all in then he will basically bleed away his chips if he keeps calling.

This was my understanding from this while I was reading the book. Correct me if I am wrong. :)

• I'm not sure this addresses the question as you are varying the stack size of the opponent and not your bet. In the book Hansen is worried about a specific opponent with a fixed stack size and is concerned about betting the right amount to make an all-in move a bad play. Maybe the math is the same, I'll try to work through it. Mar 6 '12 at 19:41

Short stacked opponents are looking for opportunities to go all in, almost BY DEFINITION.

That is, they are looking for "double or nothing" situations whereby they can either "double up" or "go home" immediately, probably to a more profitable game.

For instance, if the size of the pot is 50% of the person's stack, he can push 100% of his money to win 50% if not called, or 200% of his money, if he is called, and he wins.

It is in the interest of the big stack NOT to give the short stack these potentially profitable situations, keep the pots small, and let the law of averages "bleed out" the short stack, through blinds. So you want to create a situation where their BLINDS "overcommit." And the way to do that is to keep them "undercommitted" on other hands.