The Cost of Not Understanding Probability Theory
People who fall for this fallacy, do so because of a fundamental misunderstanding of how probability works. They combine the probability of past events (irrelevant for independent trials), with that of future events. With the example above, some people would also erroneously conclude that “tails is long due to come up” and as such would think that it’s more likely to occur.
This informal fallacy has contributed to the ruin of many gamblers over the years.
via math-blog.com