Reverse ISF theorem and Manipulation

These thoughts about manipulation keep running through my mind and it’s keeping me awake, so I decided I’d write them down.

A few months ago I got really into manipulation and made some pretty good blog posts about it. Eventually, I got more into exploring ranges and I came up with ISF theorem and explored that. Now I’ve been thinking more about manipulating opponents through overall strategy. In other words, playing in such a way that manipulates our opponent to play in a way that benefits us.

Note: Against great players most of what I write is going to be irrelevant. There is just not a lot you can do to manipulate great players because they understand what you are trying to do. BUT that doesn’t mean that this information isn’t incredibly useful. You’re not going to meet a great player anytime soon.

Balancing our opponents range and Reverse ISF theorem

Gabe once said that bigger bets will give rise to less aggression from our opponents and smaller bets will give rise to more aggression. I have found this to be true. But right now I’m going to look at overall bet sizing strategy to manipulate our opponent to balance his range.

A lot of the time when I have a draw I tend to make larger raises. Why? Because I want my opponent to balance his range passively by manipulating him to call rather than raise his strong hands and his weak hands. It gives me an oppurtunity to hit my draw and suck out on him.

BUT ha! I bet you thought when I said draw I meant a flush draw or straight draw, but you were wrong. All a draw really is is a hand that can become better than our opponents’ on a later street. So essentially, all drawing hands can be characterized as "Weak" hands.

What this all leads to is a theory that directly relates to ISF theorem. The "reverse" theorem goes something like this:

When our range is weaker than our opponents’ range, we should tend to play our hands in such a way that manipulates our opponents to play passively. When our range is stronger than our opponents’ range, we should tend to play our hands in such a way that manipulates our opponent to play more aggressively.

This explains why you see good players check hands like bottom pair or Ace high instead of continuation bet them. We want to give our hand a chance to draw out on our opponent, and by letting his check stand, our opponent is playing more passively.

Of course I’m not advocating people bet bottom pair on two streets OOP even though it’s obvious we are behind so we can draw out on our opponent . There’s only so far this theorem goes.

Un-balancing ranges:

We want our opponents to play in the most predictable way possible so we can play our range to the best of our knowledge. If we know someone has a draw, or know they have midpair, it becomes very easy to figure out what we should do with any given hand. If we know someone has a draw, top pair, mid pair, air, etc. or any hand in the deck playing against them becomes a lot harder. So what we strive to do is force our opponents to lay in the most predictable way possible with the thinnest ranges possible.

There are many ways to do this. One simple example of doing this is making a small bet size on vunerable boards. Against a player who is passive and wary to raise a top pair hand, we force him to protect that hand and raise. Therefore, when he doesn’t raise on the flop we know he doesn’t have a good hand. With much more aggressive players, we may makes pot sized bets to manipulate him to play straightforward so we aren’t faced with a balance range of draws, air, midpair hands, top pair or better, when he raises.

Another way to unbalance someone’s range is to force them to adopt a style that makes them easier to play against. For example, against aggressive players we could raise a smaller size preflop, forcing him to play much more hands and in turn bluff a much higher frequency than is optimal.

Similarly, we could make our raise size the minimum versus a nit, forcing him to play a lot more hands OOP where he would be forced to amp up aggression to not let his money go. Or, threebet a smaller size, forcing our opponent to play much more hands to my threebets, even though he’s not comfortable playing with bad hands in threebet pots.

Or we could drastically increase all of our bet and raise sizes. This forces aggressive opponents to play their hand for more of its own value, since the opponent would feel unobligated to make plays since all he has to do is wait for one hand to stack you off, when in fact the moment he raises or bets into you, you fold.

The point of this article is to make people realize that you have to go beyond thinking in a hand to hand basis. Hope this was interesting.