April 3, 2010 – 10:41 am | 7 Comments

I’ve compiled a short (just 7-pages) e-book, an introduction to the mathematics of poker. It’s basically covers how to calculate your expected value in a certain spot – starting with explaining what EV is, all …

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Home » Opponent Modelling

A Model For Folding

Submitted by on December 5, 2009 – 3:31 amOne Comment

When analyzing the last hand, I realized that I need a model to predict whether my opponent (given a certain hand) will fold. Basically a way for me to say “if he has X-X cards, given the board and this bet size, he’s Y% likely to fold”. At the moment I don’t have that model yet. But can it be done? I certainly think so.

Off the top of my head, there are a few variables to consider. First, definitely, would be the pot size and how much he needs to call (essentially the pot odds). Then the value of his hand given the board. I’m thinking that as a rough guide, you can use the percentage of hitting top pair or higher by the end of the hand to do this. I say a top pair or higher because that’s often good enough to win. You can tweak the number of outs he has according to various situations, but I think that’s a decent general guide. Those are the main variables – number of outs he has, and the pot odds he’s getting. Add in a variation for bluffing or semi-bluffing, and you have a rough model.

It’d be a crude model, for sure, but for analysis purposes, I think it could work decently enough to determine the best play in a situation. It doesn’t need to be extremely precise to be able to help in decision making. And I am going to get started working on the model.

What do you think? Can such a model be done? Or do you think it can be done, but that I’m missing some variables – if so, what?

One Comment »

  • jason says:

    to answer your question, yes. you'll probably develop an informal one as you play and observe what people call with and fold with.

    you flop a top pair on a small board and your opponent, who raised preflop, checks. it's fairly safe to assume your opponent has an over or 2 overs. at this point, you have to think about the odds that he'll hit on the next two streets. from there, you can determine what a profitable bet would be. most of the time you probably just make the bet and he folds to you, but if you have a sense of his personality (maybe he's a calling station, or he's tight and you've been raising him out of a lot of pots and feel like he's about to crack and call), you can make the raise bigger.

    some people automatically fold if their non-paired hand does not improve on the flop (some multi-tablers are like this, so if you see someone playing slow a lot at random spots, take notice and see if they're easily pushed off flops). if you're in front of them, a bet from you will only be called about a third of the time, since most flops miss. so get into hands with them, and make small flop bets. most of the time you will profit, and if they call, you at least get a solid read on their hand.

    the way you play will affect calling ranges. if your table image is tight, you'll get a lot more folds, and vice versa. if you just showed a junk hand at a showdown, you may get more callers on your next pair, and if you just showed aces, you may get folded to when you bet your rags on the next hand.

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