Gambler’s Fallacy

[hubag bohol]

Explanation

The gambler’s fallacy is the fallacy of assuming that short-term deviations from probability will be corrected in the short-term. Faced with a series of events that are statistically unlikely, say, a serious of 9 coin tosses that have landed heads-up, it is very tempting to expect the next coin toss to land tails-up. The past series of results, though, has no effect on the probability of the various possible outcomes of the next coin toss.

Example

(1) This coin has landed heads-up nine times in a row.

Therefore:

(2) It will probably land tails-up next time it is tossed.

This inference is an example of the gambler’s fallacy. When a fair coin is tossed, the probability of it landing heads-up is 50%, and the probability of it landing tails-up is 50%. These probabilities are unaffected by the results of previous tosses.

The gambler’s fallacy appears to be a reasonable way of thinking because we know that a coin tossed ten times is very unlikely to land heads-up every time. If we observe a tossed coin landing heads-up nine times in a row we therefore infer that the unlikely sequence will not be continued, that next time the coin will land tails-up.

In fact, though, the probability of the coin landing heads-up on the tenth toss is exactly the same as it was on the first toss. Past results don’t bear on what will happen next.


http://www.logicalfallacies.info/relevance/gamblers/

[hubag bohol]

The Gambler’s fallacy is the tendency to think that future probabilities are altered by past events, when in reality, they are not. Certain probabilities, such as getting a heads when you flip a (fair) coin, are always the same. The probability of getting a heads is 50%, it does not matter if you’ve gotten tails the last 10 flips. Thinking that the probabilities have changed is a common bias, especially when gambling. For example, I am playing roulette. The last four spins have landed on black, it has to be red this time right? Wrong! The probability of landing on red is still 47.37% (18 red spots divided by 38 total spots). This may sound obvious, but this bias has caused many a gambler to lose money thinking the probabilities have changed.


http://listverse.com/2010/01/07/top-10-common-faults-in-human-thought/

[hubag bohol]

For example, I am playing roulette. The last four spins have landed on black, it has to be red this time right? Wrong!

Daghan tawon kaayong natutyo ani nga sayop nga panghunahuna...