1

Poker Shrink Vol. 70: Interaction Effect

Poker Shrink

All fold to the small blind, who completes. The big blind raises, the small blind folds. Then two rounds later, same scenario, same result. Next round there is a limper, the small blind completes, the big blind raises, and both opponents fold. This is easy for the big blind. Two rounds later another limper, the small blind completes again, the big blinds raises again, and the limper reraises. Oops!

That is an example of the interaction effect. Generally speaking, in scientific research we have a dependent variable and an independent variable. The independent variable (iv) affects the dependent variable (dv). So alcohol as the independent variable affects sleep, the dependent variable. Alcohol can put you to sleep and we can demonstrate that with a study showing the effect of the iv on the dv.

Now in most experimental testing we are looking to see if the independent variable will have any effect on the dependent variable and we report what that effect is. So, does noise (iv) affect sleep? We make noise and see if it wakes someone up or perhaps prevents him from falling asleep. We give kids food with high sugar content (iv) and see if they behave (dv) any differently.

But sometimes there is more than one independent variable. As in our first poker example. The dependent variable was winning the hand. The independent variable was the other player — but when we introduced the limper, that meant we had two independent variables and we needed both of them to fold to our big blind’s raise. What is clear is that experiments get more complicated whenever there is more than one independent variable.

You take a sleeping pill, you fall asleep. If you take sleeping pill with a glass of vodka, you fall really deeply asleep. Two independent variables interact to cause a different reaction or a new dependent variable.

Here the independent variables are doing something we did not anticipate; they might actually be influencing each other. This potential is what we call the interaction effect. You raise, the limper reraises, and the small blind makes it four bets. Things have changed. Those independent variables are interacting and being very independent.

At the poker table, we are dealing with lots of independent variables and they change as they interact. For instance, the rock opening a hand in late position is not the same as that rock opening under the gun. Same player, different independent variable action. Add in another player, and now they can interact with each other and you have to consider the interaction of their positions, stack sizes, etc. And, of course, facing the player in Seat 3 and the player in Seat 7 is not the same set of independent variables as facing players in Seats 3 and 5.

Now clearly we can take this to absurd limits. With a full table of players and a moving dealer button and shifting stack sizes, very quickly the combination of independent variables makes the interaction effect something that no one could keep track of. But at a more basic level, we can learn from the interaction effect that some second and third independent variables are worth paying attention to.

Certainly, when the third player enters the hand this changes the play drastically. Which is why we often try to isolate against just one player — we want to reduce the interaction effect between those two players, between those two independent variables.

The key to using the interaction possibilities to your advantage, like any other edge you might get at the poker table, is being aware of the possibilities. When both players check to you, they put you in a position of power. Of course, now two players are also in position to check-raise you, if you bet. The card on the turn now has to miss two other drawing hands not just one. But when it does, you have two potential crying calls to increase your pot.

A famous scientist once said to his students: “Remember the important part about independent variables is that they are independent, we don’t control them and therefore they can change everything we think we know about the dependent variable.” Or about the poker game.

 
 
 

Related articles

Reader Comments

No comments

Add Your Comment
 
Online poker Tweets
  • Maria Ho

    Love all my competitors turned family left on The Amazing Race. Can't wait to watch and root them on tonight! Who's going to make the Top 3?

    < 1 min.
  • Doyle Brunson

    watching my money disappear with Baltimore Ravens. I had plus 1, got beat by 2. Balt was in the red zone 5 times and didn't make a touchdown

    < 1 min.
  • Shannon Elizabeth

    I totally forgot Thanksgiving's this week-that's right-what is everyone thankful for?

    1 minute ago
  • Shannon Elizabeth

    I think my big night tonight consists of the AMAs & my babies-I need a night to rest & figure out my week. Anyone have big plans this week?

    11 minutes ago
  • David "The Maven" Chicotsky

    Railing online and catching up on nes from around the world...going to get some grub with a friend (H.E.B.) in a bit...Venetian 2.5K tomorr

    24 minutes ago
View full list of poker tweets

Online poker rooms

PokerStars PokerStars

PokerStars Marketing Code + 100% up to $600 First Deposit Bonus + Exclusive $2k Cash Freerolls running till end 2009!

Review Start Playing
Full Tilt Poker Full Tilt Poker

Full Tilt Bonus Code + 100% up to $600 First Deposit Bonus + Exclusive $1k Freerolls until Dec 09!

Review Start Playing
Ultimate Bet Ultimate Bet

Exclusive 150% up to $1,600 First Deposit Bonus + $1,215 Freerolls for PokerNews awarding CASH & ticket to $200k GUARANTEED Tourney!

Review Start Playing
OnlyPoker OnlyPoker

110% up to $600 First Deposit Bonus + $9k in Exclusive PokerNews Freerolls!

Review Start Playing
Absolute Poker Absolute Poker

Fantastic 200% up to $500 First Deposit Bonus + Exclusive $1,215 Freerolls awarding CASH & Tickets to $200k GTD Tourney!

Review Start Playing
Sportsbook Poker Sportsbook Poker

Exclusive 100% deposit bonus up to $1000!

Review Start Playing
Carbon Poker Carbon Poker

Stunning First Deposit Bonus of 200% up to $1,000!

Review Start Playing
Bodog Bodog

110% First Deposit Bonus up to $500!

Review Start Playing
PlayersOnly PlayersOnly

110% up to $650 First Deposit Bonus!

Review Start Playing
RPM Poker RPM Poker

200% First Deposit Bonus up to $1,000 + Exclusive Freerolls!

Review Start Playing
Cake Poker Cake Poker

110% up to $600 First Deposit Bonus

Review Start Playing
Advertisement