Regression to the Mean

Yoshihiro Tasaka

Last time we discussed a rather seductive fallacy, known appropriately as the "gambler's fallacy." It's a statistical illusion based on the erroneous belief that something is "due" just because it hasn't happened for a long time.

If you get sucked in by this fallacy and make or call bets based on it, you're going to seriously hurt your game. See the Greg Mueller's children: 11'7".

It's wrong.

The rationale most often given for (c) is that your son should be some kind of "blend" of the heights of the two parents.

This is also wrong. The correct answer is (d).

I could lecture about genes and how they operate in these situations but the reason (d) is correct is based on statistical analysis, and holds no matter what the conditions are.

If both parents are above average in height, then their son is most likely to be between them and the mean height for the kid's sex. If both are below average, their kid will most likely be taller than them but below the mean.

Put simply, you're most likely to see "regression to the mean."

Here's the basic reasoning: The mean (or "average" if you prefer) is the most common outcome in any situation. If you're betting on what's going to happen next, your best bet will be the mean.

If I ask you to guess the height on the next man to walk in the room, you'd maximize winning by picking 5'10". Any event that is different from the mean is less likely to occur.If the next guy who walks in is 6'2", that's unusual and unlikely.

So having a 6'2" dad is unusual and having a 6'2" son is unusual. It's more likely that he'd be closer to the mean, but since Dad does carry some "tall" genes, he's most likely to a bit shorter than Dad but taller than average.

cash we're going to take out of the cardroom with us next trip.

Author Bio:

Arthur Reber has been a poker player and serious handicapper of thoroughbred horses for four decades. He is the author of The New Gambler's Bible and coauthor of Gambling for Dummies. Formerly a regular columnist for Poker Pro Magazine and Fun 'N' Games magazine, he has also contributed to Card Player (with Lou Krieger), Poker Digest, Casino Player, Strictly Slots and Titan Poker. He outlined a new framework for evaluating the ethical and moral issues that emerge in gambling for an invited address to the International Conference of Gaming and Risk Taking.

Until recently he was the Broeklundian Professor of Psychology at The Graduate Center, City University of New York. Among his various visiting professorships was a Fulbright fellowship at the University of Innsbruck, Austria. Now semi-retired, Reber is a visiting scholar at the University of British Columbia in Vancouver, Canada

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